Another FGMM Clone thread. Accuracy Issues

[Av8rgrip]

I want to clone as accurately as possible Federal Gold Medal Match .308 ammo with the Sierra 175 smk. I know this subject has been beat to death, but I am having accuracy issues and I dont understand why. I cant seem to find an answer from searching the forums.

Firearm: Rem 700 SPS Tactical, 1/10 twist, 20 inch heavy barrel. Suppressed.

Components: Fired FC brass (I dont separate by number of firings), IMR 4064, FED 210M primers, 175 SMK, 175 Nosler CC, 168 SMK, 168 AMAX, and 168 Nosler BT.

Background: My gun consistently shoots .5 MOA with Factory 175 and 168 FGMM. I have successfully Cloned the 168 grain .308 FGMM with the above components the only difference being a slightly different POI from the SMK to the AMAX, and Nosler BT, but the SMK reloads match factory POI. Muzzle velocity and accuracy match. I have Factory FGMM that I am using to match COL. If memory serves it is 2.805. When resizing I am getting a shoulder measurement of 3.620 or so while factory is around 3.617.

I have been trying to Clone the 175 FGMM but am running into Accuracy issues with both the 175 SMK and 175 Nosler CC. 41.8 gr of IM4064 seems to match the muzzle velocity but Accuracy is more along the lines of 2-3 MOA.

I have been lead to believe that this may be a powder issue for my gun. I plan on trying RL15 the next time I can find some but that may be a while considering the current state of affairs.

Is there anything else I might need to look at?

 

[918v]

Depending on the lot, you may need more than 41.8 grains of 4064 to reach the accuracy node, regardless of observed velocity. There is more to accuracy than velocity. Also, play with the coal. Sometimes 2.795” does the trick.

 

[918v]

40.8grs of ARComp is good too.

 

[Doom]

I worked up this combination in my SPS Tac (1 in 12) and found accuracy at about 42-42.2 gr of 4064. I didn't record COAL but I believe its about the 2.795 mentioned above. Not real comfortable on the POI shift but I was looking for the FGMM node. My 168 node is quite a bit wider.

 

[Av8rgrip]

Depending on the lot, you may need more than 41.8 grains of 4064 to reach the accuracy node, regardless of observed velocity. There is more to accuracy than velocity. Also, play with the coal. Sometimes 2.795” does the trick.

Ok, I went back and reviewed the targets I could find. I did work up to 42.2 at one point but not seeing much accuracy improvement in the one group I could find. I settled on 41.8 as it seemed to be the "most" accurate. What I did notice though is that my 41.8 gr reloads have shots that group in the same location as the Factory loads, but there are "flyers" that open up the groups. Could be me, but I don't feel that I am throwing the shots and my groups with Factory loads and 168 hand loads group very well. Is there anything with the brass that could throw a shot off by and inch or two from what is a consistant POI?

 

[GIXXER2000]

Never liked 4064 in my 308 AIAE 26 in 1-10. I shoot Varget and have used 4166 which seemed to be abut the same as Varget. But as we all know every rifle is different.

 

[918v]

Ok, I went back and reviewed the targets I could find. I did work up to 42.2 at one point but not seeing much accuracy improvement in the one group I could find. I settled on 41.8 as it seemed to be the "most" accurate. What I did notice though is that my 41.8 gr reloads have shots that group in the same location as the Factory loads, but there are "flyers" that open up the groups. Could be me, but I don't feel that I am throwing the shots and my groups with Factory loads and 168 hand loads group very well. Is there anything with the brass that could throw a shot off by and inch or two from what is a consistant POI?

View attachment 7467934View attachment 7467935View attachment 7467936

Then play with the coal, go up and down in .005” increments measuring the seater stem, not the bullet tip.

 

[Buzzinga]

I want to clone as accurately as possible Federal Gold Medal Match .308 ammo with the Sierra 175 smk.

1. Get a reliable average velocity for your factory loaded Federal Match 175 SMK's.
2. Using a COAL of 2.800", increase/decrease your charge weight of IMR4064 to match the factory load. Don't worry about accuracy.
3. Adjust seating depth out in small increments 2-3 thousandths. Your groups should begin to shrink and then open back up. Pick the best group as your clone.

 

[Plinker 73]

I acquired sone FC GMM primed brass and powder from pull down. I was told the powder was RL 15. I loaded 41.5 grains on a 175 smk hp 2.800 oal with great results .
Rad

 

[nn8734]

I currently use a similar load to FGMM in my Mk11. Consists of 175 smk, 42g RE15, 210M primer, Federal 1x fired case, fl sized (.003-.004 shoulder bump), casehead-ogive measures 2.150”. SD is typically 10-12 over 5 random rounds and is effective to 800 yards when I do my part.

 

[Av8rgrip]

Just to clarify. Right now I am trying to match Factory 175 FGMM as it shoots extremely well out of my gun. I would like to match it as closely as possible as I would like to be able have the option of reloading or buying factory loads without going through the process of re-zeroing or re-dope-ing every time. Right now I have plenty of 4064 and match primers and bullets. As we all know there are times like when we can find factory ammo or reloading components easily, normally you can find one or the other or both. Unfortunately right now, everything is in short supply.

 

[Av8rgrip]

I have heard both, but the latest is that RL-15 is closer or what Federal is currently using. Not that they are using exactly what is available commercially.

 

[bunsen27]

You're in the neighborhood for the clone load.

How are you resizing your brass? How are you setting neck tension? annealing?

OCW Load Recipes... - Dan Newberry's OCW Load Development System

Dan Newberry OCW or Optimal Charge Weight Load Development method or system for handloading, reloading, bullets, brass, powder, primers, accurate handloads.

optimalchargeweight.embarqspace.com

.308 Winchester using IMR 4895
150 grain bullet, 46.6 grains (extrapolated from following loads, untested at this writing)
155 grain bullet, 45.6 grains
168 grain bullet, 43.6 grains
175 grain bullet, 42.4 grains
178 grain bullet, 42.0 grains
178 grain bullet, good match load... use 41.7 grains with Lapua brass, 41.5 with FC brass.

.308 Winchester using IMR 4064
168 grain bullet, 42.8 grains
175 grain bullet, 41.8 grains
(these replicate Federal Gold Medal, use FC or Lake City brass)
We like 178 grain bullet and 41.5 grains in FC or LC brass

.308 Winchester using Varget
155 grain bullet, 47.8 grains
168 grain bullet, 46.0 grains
175 grain bullet, 45.0 grains (an all around favorite)
180 grain bullet, 44.1 grains
200 grain bullet, low node 41.5 grains (10 twist barrel)
200 grain bullet, high node, 43.1 grains (10 twist barrel)

CCI 200's, BR-2's, and Federal 210's work well with Varget

 

[Av8rgrip]

You're in the neighborhood for the clone load.

How are you resizing your brass? How are you setting neck tension? annealing?

OCW Load Recipes... - Dan Newberry's OCW Load Development System

Dan Newberry OCW or Optimal Charge Weight Load Development method or system for handloading, reloading, bullets, brass, powder, primers, accurate handloads.

optimalchargeweight.embarqspace.com

.308 Winchester using IMR 4895
150 grain bullet, 46.6 grains (extrapolated from following loads, untested at this writing)
155 grain bullet, 45.6 grains
168 grain bullet, 43.6 grains
175 grain bullet, 42.4 grains
178 grain bullet, 42.0 grains
178 grain bullet, good match load... use 41.7 grains with Lapua brass, 41.5 with FC brass.

.308 Winchester using IMR 4064
168 grain bullet, 42.8 grains
175 grain bullet, 41.8 grains
(these replicate Federal Gold Medal, use FC or Lake City brass)
We like 178 grain bullet and 41.5 grains in FC or LC brass

.308 Winchester using Varget
155 grain bullet, 47.8 grains
168 grain bullet, 46.0 grains
175 grain bullet, 45.0 grains (an all around favorite)
180 grain bullet, 44.1 grains
200 grain bullet, low node 41.5 grains (10 twist barrel)
200 grain bullet, high node, 43.1 grains (10 twist barrel)

CCI 200's, BR-2's, and Federal 210's work well with Varget

well, short answer, I’m not. Just running it through the resizing die and confirming the neck is set back enough. I did look at neck tension at one point and it seemed ok. Dabbled with annealing but thought I might be doing more harm than good, as didn’t know if I was doing it uniformly.

 

[bunsen27]

I asked because I was seeing something similar when working up loads with new LC brass earlier this year. I kept getting occasional flyers. Ultimately it was due to neck tension.

 

[918v]

Right now whatever is in there is closer to AR-Comp. FGMM had 3031 in the 80’s, 4064 in the 90’s, and RE-15 in the 2000’s.

 

[918v]

Just to clarify. Right now I am trying to match Factory 175 FGMM as it shoots extremely well out of my gun. I would like to match it as closely as possible as I would like to be able have the option of reloading or buying factory loads without going through the process of re-zeroing or re-dope-ing every time. Right now I have plenty of 4064 and match primers and bullets. As we all know there are times like when we can find factory ammo or reloading components easily, normally you can find one or the other or both. Unfortunately right now, everything is in short supply.

Plot coal vs charge weight otherwise you’ll never get it. This is what I do:

 

[Buzzinga]

Sleuthing the Federal Gold Medal match load... Mk 316 Mod 0?

Okay... the self appointed mall cops of reloading might want to go watch a rerun of Gomer Pyle about now... :) For the rest of us, here's a short video we made today... Sleuthing the Federal Gold Medal Match long range load recipe. - YouTube Dan

www.snipershide.com

 

[Greg Langelius *]

My FGMM clones begin with F/L resized commercial brass and a large rifle match primer. I like IMI, IMI Match, PPU, and Starline. The IMI stuff uses crimped pockets.

Add 168 SMK at 2.815" OAL and 43.5gr of IMR-4064, or 175SMK at 2.815" OAL and 42.2gr IMR-4064. For the 168, try a direct substitution with a Speer 168 Gold Dot.

That's what I'm using in my 20" 1:10" PA-10. and 24" 1:10" Savage 11VT.

The 2.815" OAL was developed as the longest which would reliably feed from SA M-14 magazines. So far, it's also worked in everything else I've tried.

Greg

 

[Av8rgrip]

I asked because I was seeing something similar when working up loads with new LC brass earlier this year. I kept getting occasional flyers. Ultimately it was due to neck tension.

It might be worth another check. If I remember correctly, I measure then case mouth, then seat a bullet and check again. The difference is the neck tension. What is acceptable differences?

 

[Av8rgrip]

So, if it's not 4064, and that's what you are getting poor results with but you are using the same bullet, case, and COAL, maybe try RL15

If I could find a lb locally I would buy it and try it. I have 4064 on hand, plenty, and it works well in my 168 loads and others seem to have good results behind 175s.

 

[Doom]

The 168 FGMM I took down a couple of years ago had 42.8-43 grs of a powder physically identical to IMR4064. Was it 4064, I can’t say but 43 gr of my 4064 matches it. I know Dan Newberry broke down the 175 and it was not RL-15.

 

[Claluja]

If you want to "clone" FGMM, try the AR Comp as suggested above.

 

[308Gunner]

I ended up at 41.7gr of 4064 and 2.795 in a 1-10 Broughton

 

[Ryridesmotox]

Just a point I noticed in the original post... you said you don't sort by number of firings and don't anneal.

I'd wager that you have cases with pretty large swings of neck tension. I would try and separate them by number of firings, or how hard it was to seat a bullet in the case. Just a though.

Or you could anneal them all.

 

[Doom]

Looking at the targets I’ve seen this issue before. Tried to blame it on .... but the real problem was the trigger operator. I can’t say that’s the issue here but I doubt its a powder issue. I will say that brass prep may be a contributing factor and I would address that.

 

[Av8rgrip]

Looking at the targets I’ve seen this issue before. Tried to blame it on .... but the real problem was the trigger operator. I can’t say that’s the issue here but I doubt its a powder issue. I will say that brass prep may be a contributing factor and I would address that.

It could be me but every time I shoot factory loads my groups are significantly better, so I’m leaning toward reloading process. Many people seem to have had good results with 41.8ish of 4064. I have considered neck tension and resizing in the past, and tried to manually anneal but wasn’t comfortable that I was doing it consistently. I broke down and ordered a machine and I have started collecting once fired brass and separating it. I will see if this helps.

 

[j-dubya]

RL-15 is the powder in M118LR (Lake City) over the years. Not the Federal loadings. The Federal military load is Mk316. Maybe was originally 41.75 of 4064 like the commercial GMM 308 variant, but not in any of the lots I’ve seen over the years. The commercial 7.62 version [and military load] has always been hotter, with more powder, in order to match M118LR. I’ve seen anywhere between 42.5 and 43.5 for the 7.62 load. Recent stuff looks a lot like AR Comp, but the powder in various lots I’ve pulled down over the last decade had a greenish hue. I’ve never seen anything resembling 4064 come out of Mk316 or the commercial 7.62 GMM. However, we all know it works well and use it in the clone loads, including myself.

M118LR is a different ammo completely! And it’s had its charge reduced over the years.

 

[918v]

FGMM used RE15 in the past

 

[Doom]

The reality is that RL-15, Varget, 8208XBR, 4064's, 4895's and several others are all great powders in the 308 with 168 and 175/178 bullets. Unfortunately a lot of these powders are not REACH compliant and will probably go by the wayside in the not too distant future (no, I don't have any inside info, just reading the tea leaves). If I were just starting out on this caliber today, I would be looking at IMR4166, AR-Comp or VV140. I haven't seen any indication that ADI has made any attempt to make compliant powders which leads me to wonder if that is part of the reason Hodgdon took over Western for access to Eurenco powders.

 

[Ryridesmotox]

Wtf is reach compliant?

 

[spife7980]

Wtf is reach compliant?

Google really only returns results on it when googled

Registration, Evaluation, Authorisation and Restriction of Chemicals - Wikipedia

en.m.wikipedia.org

 

[smoothy8500]

It's like California prop 65. It's probably the solvents used in the manufacturing process that leave residues, thus causing cancer, reproductive harm, etc.

Edit. Looks like it got answered while typing.

 

[Doom]

Reach in a nutshell, is a EU set of regulation set up to save Europe from potentially harmful chemicals. It requires registration of all produces that have chemicals, many of which are banned for use, storage or import. Most IMR (GD Canada), Hodgdon Extreme (ADI), St Marks (older), powders are not complient. The IMR Enduron, Alliant Power Pro, VV, and most European powders are.

I have seen ADI is abandoning some pistol powders and rebuilding production facilities.

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