Reloading issue for the RFB

Discussion in 'RFB High Efficiency Rifle' started by Mike Axle, Aug 25, 2017.

  1. Mike Axle

    Mike Axle New Member

    1
    Apr 4, 2012
    I have read many posts of people who successfully reload for the RFB. I am an experienced reloader but have not had any luck with my RFB. The issue Im having is I get signs of high pressure (cratering on the primer) with any load I have tried listed in the reloading books. I have been reloading for my M14 for many years with no issues. I talked to my gunsmith and he said this could be due to a light firing pin strike. I am using lake city brass and CCI primers and hand weigh each charge when load testing. Anyone else have this issue? Any ideas on how to fix?
     
  2. ronmar

    ronmar Well-Known Member

    Oct 2, 2010
    I don't think there is a fix. You may note this same effect on factory ammo. I think it is a factor of the firing pin strike as your gunsmith noted and the fit of the bolt face to the cartridge base(and immediately around the firing pin) when chambered. Also since your LC brass originally held crimped primers, this may effect how the reload primers now seat in the now uncrimped primer pocket. Obviously if you are loading to a known spec, you are not getting actual overpressure and if you fire one of those rounds thru another rifle you will probably not see those same cratering effects... Reloading for the RFB You are also going to find your brass failing faster than normal as it's "generous" chamber makes for very expanded and stretched brass and a VERY difficult resize. This will cause the brass to work harden and fail faster. I have also been reloading for decades and experienced my only ever case failure(neck separation) reloading for the RFB. Keltec did the worst disservice to the RFB(and it's purchasers) by NOT reaming the RFB chamber and throat to a SAMI spec... If it had gotten that one detail, I think it would be easilly sub MOA.

    IMO the best way to reload for the RFB is to not do it:)... If you must, I would designate that brass as RFB only and only neck size just enough to get it to hold a bullet long enough to crimp it in place. Basically leave the brass sized to the RFB chamber which will make reloading much more enjoyable and way easier on the brass. Also IMO reloading LC brass for the RFB is a terrible waste of good brass:) Save that for a good bolt gun or a NM M-1A...

    As always, very much MY $.02
     
    Mike Axle likes this.

  3. MightyHunter

    MightyHunter Member

    65
    Jun 15, 2015
    I have had great success with a custom load for my gen 2 RFB. I use only commercial brass and IMR 4166 powder behind a Hornady SST 150 grain bullet. No signs of over pressure. I have chronograph this load in hot weather and cold weather with little variation in mv. The even better finding was that no gas adjustment was required from hot to cold with this load. It cycles great with no dented case mouths. I tried many load combinations with limited suscess before I hit on this one. I knew from the start that this was a gun that requires tinkering but there were times that I got so frustrated I considered selling the gun. The only reason I am writing this is to say that it is possible to develop a load which operates flawlessly (at least in my RFB) I am currently developing a subsonic load to use with my AAC SR-7 suppressor. So far there have been some interesting and unexpected results but that discussion is not what this thread is about. Please do not hesitate to PM me if you want to discuss further.
     
  4. Mattitude

    Mattitude Member

    49
    Nov 23, 2015
    central NC
    I get consistent sub-MOA 5 shot groups with my handloads out of my RFB using IMR3031 & 168gr AMAX projectiles. My biggest obstacle when developing a load is that KT uses a 7.62 chamber which is longer than a .308 chamber and on top of that the FAL magazines really limit the cartridge OAL. What I cannot do is seat the projectile out enough to properly fit the chamber so as not to have as much as a jump to the rifling. I'm also using commercial .308 brass and full length sizing with a small base die and haven't had any issues. 7.62 NATO brass is also thicker than commercial and also has less capacity so if you are to continue using NATO brass you might want to reduce your starting load by 10% of the minimum and go from there and see if you are still getting cratered primers. Keep in mind that cratering isn't always a sign of overpressure. I had a Rem700 that would crater the primers even with factory ammo but was within specs.
     
  5. lilwoody

    lilwoody Member

    72
    Jan 2, 2016
    Florida
    IMR3031 is the best powder for this rifle.
     
  6. ziggomat

    ziggomat Member

    3
    Apr 7, 2016
    France
    hello , i give you my feedback, because i had a near issue.

    more taht the cratering on my reload ammo my RFB succes to drill the primer ( and this without overpressure)

    this weapon is manly build for military usage , and primers on military ammo are very strong ( i dont speak about fire powerfull but about the strength/solidity)

    first of all you must verify that the head of the striking pin. This one must be very clean, smooth and little bit spheric.

    if it's not the case, polish this one.

    second step, verify the hole of the firing pin on the bolt , it not do have burrs, if not you must burr-free with drill bit by example, but very soft , not elarge the hole.


    because if you have some burrs, this do like a die cut when the presure puch the primer on it.

    and when the striking pin isn't have a good surface state this weakens the primer.

    you must know you have differents solidity of primer, by example, wichester primer are very soft and have a hole easyer, while the CCI primer it's more strong that wichester and Federal match more stronger that CCi.

    other things , on a half-auto the striking pin isn't launched like bolt action but it's a hammered stiker and you have lot of free-space between the striking pin and the bolts who allowe to the primer to expend in this space and increase the possibility to produce a hole.

    by experience with the same ammo , in the RFB have a hole or cratering and not in a bolt action.

    evidently more hight is your load , more hight is your chance to have a hole even without have an overpressure.

    in last step you may change the two hammer springs to decrease the load by 50 %.

    I did on my RFB and i always shoot with not fault event with strong primer like CCI or FEDERAL.

    on the other side, i din't try with winchester to know if my RFB drill the primer again

    but i will try , because winchester give me good result , it's more easyer to buy and it's very not expensive.

    also , the change of the two hammer spring reduce the weigth of the trigger ( and that's so cool ) and need less gaz system to reload and reduce the mechanical constraints.



    but the cratering spoken up above is due to the space between the striking pin and bolt and this effect is more important like you have more space , hight load and soft primers ( also verify the state of your usure state of your pin)

    By the way, for my reload the best powder it's initially use for .223. Why, because the barrel is short and with powder for .308 i need to up the load to have the same velocity and i had a big flame at the muzzle break that i have not with 223 powder.

    because we have a short barrel the powder must be more fast for not burn outside the barrel.

    My powder it's "ReloadSwiss RS40" and i use Lapua senar Bullet 167gr or nosler 168gr HPBT.
     
  7. anm2_man

    anm2_man Active Member

    118
    Aug 6, 2012
    Phoenix AZ
    I've been shooting my reloads in my RFB, for the last 6 years with no issues. Been using H4895 or IRM4895 (Note they are not the same). But both have functioned with no issues in my GEN 1 RFB. Here are the Specs that I've used:


    FMJ Boatail Ball 145gr 2.8 H4895 42.5gr LC 2734 RFB
    FMJ Boatail Ball 145gr 2.8 IMR4895 43.5gr LC 2644 RFB

    Been using shot once Lake City Brass and the #'s following it are the chrono results.

    But remember your mileage may Vary !!!
     
  8. GKha

    GKha Member

    7
    Sep 15, 2014
    Canada
    Hopefully I don't take too much flak for reviving this thread but I will add my resent experience to the mix.

    I have an RFB-C the Canadian version that is stamped 308Win.

    When I first got the rifle it was piercing primers as well. KT replaced the bolt. Out of spec firing pin hole allowed the pin to protrude too far. Since then no issues with pierced primers.

    I use this rifle for both range time and hunting. Range ammo has been mostly surplus 7.62 Nato and it ran well. Most of my load development focused on hunting loads. My final hunting load was as follows (use at your own risk):

    Brass: Federal (just because I had a lot of it)
    Primer: Remington 9 1/2 (just because I had a lot of them)
    Powder: Varget 45.5gr
    Bullet: Nosler Partition 165gr

    This load groups around 1.5MOA which I am happy with given its a bush hunting rifle. I went as high as 46gr of varget during load development with no pressure issues. I also tried Federal Match primers with no noticeable difference on paper.

    One point to note. Initially I struggled with getting my groups down. It was not the load that was the problem. It was me adjusting my shooting technique to work with this rifle. Its a bulpup, its short its harder to shoot than a traditional rifle.

    Here is some info from my labradar on 5 rounds fired at the range yesterday with this load:
    2620
    2601
    2616
    2621
    2623

    Stats - Average 2616.18 fps
    Stats - Highest 2622.99 fps
    Stats - Lowest 2601.06 fps
    Stats - Ext. Spread 21.93 fps
    Stats - Std. Dev 8.9 fps

    Due to the fact that while hunting I load and unload the rifle repeatedly and the lead tips on the Nosler partitions get beat up, I am now developing load using Nosler Accubond 165gr bullets. This is a work in progress but looks promising as my initial tests got me to 1.5MOA.

    One thing I did different this time is I only neck sized the brass. This was a show stopper for me. The bolt would not close on more than 50% of those rounds. I was hoping to get away with neck sizing but no luck. I contribute this issue to the fact that Federal brass is soft and expands considerably (does not last more than 3 firings in the RFB), and the chamber in the rifle is fairly rough. This does not help.

    Had a lot of success hunting with this rifle.

    Hope this adds to our collective RFB knowledge.
     
    MightyHunter likes this.
  9. ronmar

    ronmar Well-Known Member

    Oct 2, 2010
    The chamber is the most disappointing part of the RFB IMO. If they would have cut it to a SAMI spec .308, I am confident this gun would comfortably shoot MOA or better.

    The overly long chamber throat is the real kicker and what is messing with your reloading. You have to push the neck and shoulder back a bit and that is what kills the brass. You will see neck separations if you go more than 3 reloads as it is really hard on the brass. I wont reload for the RFB anymore.

    I don't think you are going to improve much on 1.5 MOA(I wasn't able to either:() The bullet having to jump that long gap in the throat before land engagement is always going to randomize bullet flight. I think that is why steel cased ammo shoots very well in this gun, the case/neck is stiffer and the bullet gets a more consistent jump into the rifling because of this...

    It is never going to be any better than minute of bad guy accurate:)
     
    Liberty4Ever and MightyHunter like this.
  10. GKha

    GKha Member

    7
    Sep 15, 2014
    Canada
    Ronmar,

    I agree. After some tweaking I managed to shave of a little off my groups. had some consistent 1.2-1.3 mao groups with the 165 accubond on 44.4 varget. I'm pushing the SAMI pressure limit with this, however no pressure signs. What is interesting is that the nosler website lists max loads for the 165 partition and accubond as the same. However running it through QuickLAOD all things being equal the accubond load results in higher pressure than the partition. That is interesting. I digress.... bottom line is my load development stops here. anything under 1.5 is quite satisfactory for the application of this rifle.

    I'm curious about your steel case experience. When I ran steel case ammo through mine I had some stuck cases. The chamber in mine seems especially rough. I can see the tooling marks on the shoulder of ejected brass. Do you know of anyone that honed the chamber on one of these. given the chamber specs I would be hesitant to remove any material honestly.

    I attached one of my targets.
     

    Attached Files:

  11. flyer

    flyer Member

    45
    Nov 30, 2015
    The factory FGMM 175's have produced sub moa performance for me. My manufacture date was later than most I see here so, maybe, they tightened up the chamber. I had to adjust the GB for it but brass came out in excellent shape. I had to re-adjust the GB after the rifle smoothed up - about 200 rounds - after I noticed an increase in recoil and dinged case mouths but, now, all is well. I now reload for it using 175 SMK's and a standard book value of Varget. If you can pick one load to shoot and adjust the GB for it, the RFB does well.

    Keltec RFB vs 18"x24" steel @ 600yds.
     
    Last edited: Sep 6, 2019
    Liberty4Ever likes this.
  12. ronmar

    ronmar Well-Known Member

    Oct 2, 2010
    Steel cased Tula 147gr runs great for me, sub 1.5 consistently and feeds just fine for me. At under .50 a round it is pretty hard to beat. About the only bad things I can say about it is it does not use as thermally stable a powder as Varget and you can note a little vertical POI shift from cold to warm. That and its dirty, but the RFB is so easy to strip and clean that isn't a real issue...

    I have thought about unloading a few and swapping out the powder just to see how they would perform, but I have a lot of other projects that are higher on the priority list than that...

    “Polish chamber” is a pretty common/standard note when people have sent their rifle back to KT for service...
     
  13. flyer

    flyer Member

    45
    Nov 30, 2015
    Quality ammo has proven to be the key to accuracy - for me at least. FGMM and some of the Federal hunting rounds along with my reloads in Federal brass have given me enough accuracy to win a couple of "golf ball" matches here locally and it surprised a few bolt gun shooters. I wouldn't shoot steel case through anything - never tried it - but, I've heard of some very good accuracy from it with the RFB... I just use FGMM 175 or 168 and have had excellent results. FWIW.
     
  14. ronmar

    ronmar Well-Known Member

    Oct 2, 2010
    I would agree with a proper chamber quality ammo/reloads are key, so your RFB must have a better chamber than mine. I have shot competitively and reloaded to match quality most of my adult life(even did 2 years on the USCG rifle and pistol team competing at the national level).

    I have a heavy barreled savage that with the OCW reload I developed in 168, shoots 3/8 MOA. Still need to work up the load for 175, also way down on my current priority list unfortunately. Even the most precise reloading wont fix the 0.1” jump from max loaded length to land and groove engagement that I measured on my RFB...

    As for steel, I have only ever played with it when I got the RFB. In a precision chamber, it is certainly not going to shoot as well as more precision loaded ammo. But it is usually loaded for MG so it is usually pretty reliable, at least when fresh and the Tula I buy is current production not surplus with questionable storage history... I was surprised how well it shot which drove me to figure out why it outshot my best hand load attempts...
     
  15. flyer

    flyer Member

    45
    Nov 30, 2015
    A standard load of Varget and 175 SMK's has produced outstanding accuracy from my RFB. Occasional 1/2 moa at 100 to 600 yards is what I consider "outstanding" from this platform but is not something I see every time at the range. However, with my best loads, 1 moa is pretty easily achievable. I'm jumping the 175 SMK .16 at a COAL of 2.80 - 2.82 is about max mag length and 2.96 is touching lands. Maybe I just got a good one but I've been very happy with it. It's become one of those that I'm keeping.
     
  16. ronmar

    ronmar Well-Known Member

    Oct 2, 2010
    The 175’s also have a longer body so they may bridge the gap a little more consistently.
     
  17. TolusD

    TolusD Active Member

    53
    May 20, 2019
    I don't reload, but I shoot a lot of surplus 7.62 NATO and I've found that even in my 308 bolt gun, MEN German ammo is the most consistent, most accurate, and cleanest I've found.

    https://www.sgammo.com/product/308-...-nato-147-grain-ammo-made-germany-men-men762a

    It's 56¢ a round so not bank breaking and the brass is immaculate with hardened shoulders so maybe that's why it work so well in both of my guns? That said, I want to hunt with this rifle and as I said, I don't reload so I'm looking for the best commercial load for it. Any suggestions there? I'd like a solid copper bullet if possible.
     
  18. odinforever2000

    odinforever2000 Well-Known Member

    361
    Oct 6, 2011

    I recently did this 10 shot group (while adjusting adjusting elevation with my 3x optic. Squeesed off a couple kinda fast (3 seconds between 2 shots) on the second (top) group..Magtec Sniper with 168gr Sierra Otm.. Group size average is 1.6moa.

    I'll try Gmm..I also wanna try some of the Varget loads mentioned here for 168's (I have a bunch of Elds in my cave)

    Hoping the guy who makes the handgaurd for the Rdb has a sellable and longer handgaurd for the Rfb soon ;D
     
    Last edited: Nov 26, 2019