My pet load for my Rem 700 LTR (20") has been a quite hot;
26.0 of ADI 2206H
Lapua Match Case
CCI 400 primer (now using CCI 450)
At 88 F / 29.93 inHg / 43 % humidity, this load gives me a consistent 3100 fps.
Not surprisingly, I've had some trouble with cratering and blown a few primers, and have decided to go over to CCI 450 magnum small rifle primers as the thicker cup will all but fix the cratering.
Has anyone else done such a change in the past?
Is there an increase in pressures with the 450 over the 400, or is it just a thicker cup?
I guess I'm just trying to NOT have to re-develop the entire load, which if I don't get some advice from here I may have to do, but if anyone has had a similar experience, please offer your suggestions.
Update for anyone who's interested;
Now using CCI 450 primers
No difference in accuracy and MV near to exactly the same as previous load.
No signs of high pressures, slight cratering still present, but no issue.
70gr Berger VLD (same BC as the 77gr SMK)
Mag length (2.260")
Results from my 20" Noveske AR w/ 10x optic in 65*F, 500' DA, zero wind, good visibility, no mirage; prone supported:
2900fps (ES and SD an amazing 5 and 2 respectedly - not sure if I can continue to get that low)
0.50moa at 200yds (multiple bullets thru same hole)
moderate pressure signs (some flatness in primers)
WORK UP. IT IS A 5.56 PRESSURE LOAD - DO NOT USE IN .223 CHAMBER
both of these loads will do .25-.5 inch 5 shot groups at 100 depending on how I am doing that day. I just developed these in the last month, and plan to explode some p dogs with em next week. I will update then!
Just an FYI that Alliant finally added a bit of 2000mr data for the 77 smk. 25.2 grains at 2.26(mag length) is getting a published 2856 fps. I know that with the 175 smk 308 load, I was over their published velocity a grain and a half below the recipe. Seems promising, I'll prob try it with some hornady 75 gr bthp once my new upper arrives, and will post a full report. This stuff seems to get more accurate the more you pack the powder in. Come on 2900!
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: FIREMEDIC27</div><div class="ubbcode-body">Does anyone have any load data for the Speer 55g TNT HP in .223 Rem? My book has nothing......</div></div>
im running a sierra 55gr hpbt 26.8grs of varget nosler brass and cci 400 primers loaded mag length out of a 20 inch kreiger 1 in 9 twist, holds 3/8 at 100yds on calm winds. I know it isnt the speer bullet, but another option, hope this helps. you can slso go to hodgdons web site for load data . Loaddata.com is good but a paid site
AR15 LMT MRP
COAL 2.253-2.261" (It isn't tha picky. I just picked the range from the shortest to the longest in my last 50 loaded rounds.)
After fireforming win brass this load will shoot 5 shots 1/2 moa easily and with quite a few sub 1/2 moa. No velocity yet. New .223 win brass in this rifle will hover right around 1MOA. I'm guessing it's the difference in headspace.
I just tried some Accurate 2460 w/77gr SMK's and got super velocity up to 2834 @25.5gr but the accuracy was super shitty.
I have been getting just over .5" with 77gr SMK's and 24.2gr of Reloader 15. I haven't chronoed it yet but Im guessing its around 2650ish.
Im gonna try the 8208XBR next.
Oh ya the rifle details is a 18" Rainier (Shilen) ultra match Gisselle SSA and Viper PST. It started out to be a MK 12 mod O but I ran out of money and it got a JP forend and no BUIS. I have a PWS comp. on it but soon it will be sporting a Thunder Beast can.
My attempt to copy Mk262 ammo
HCS Mark 12 Mod 1
LC brass (cheaper than win brass, real Mk262 is stamped WCC fwiw)
CCI #41 primers
2.26" Cartridge Overall Length
1.75" Case Length
Average of 27 rounds, DA 7474'
Slightly crunching powder, medium cratering, medium flattening. I could go a bit more, but this load shot 3/4 minute and I'm cool with that. The SW Ammo was definitely more accurate, at least 1/2 MOA. I didn't think it was that fast (the SW Ammo). I might back it off to 25gr Varget and see if it tightens up a bit, now that I think about it
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KSKevin</div><div class="ubbcode-body">Enhanced accuracy of my load for Hornady 53g Vmax a bit by using H4895 instead of Benchmark.
Hornady 53g Vmax kissing lands
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: aviumvenator</div><div class="ubbcode-body">23.9 AA2520
PRVI 75 HPBT
LC often fired brass
Trimmed, primer pocket uniformed and deburred inside
CCI 450 primer
Do you have any groups you can post? .125 MOA is ridiculously good for a bolt gun and almost unheard of in a Semi.</div></div>
Yes, .125 MOA would be awesome and I would post pics if I had them but the 1/8 I posted referred to the barrel twist...1 in 8. My bad on the typing. I have been able to shoot the rifle 1 MOA or better.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gungneer</div><div class="ubbcode-body">27.5 gr Varget
55 gr bulk fmjbt
Lake city Brass
2.260 +0/-.002 Case head to meplat
My 3 gun round used in m4 16" 1:9
for targets 2yd to 500yd </div></div>