Max loads using a 125 sierra

[Oldmanpaintball]

I was wondering what the max load in a 300 whisper/fireball is using H110 and a 125. I am using 22.0 grains right now but I feel I may be able to push it a little further. I would like to have a 200 yrd deer round.


OMP

[320pf]

OMP,

The max load in the Sierra Reloading Manual for the 125g Sierra Prohunter is 19.0 g of H110. This load gives about 2250 to 2300 fps. I have loaded them up to 20 g to get about 2300 to 2350 fps from a 16 in. barreled AR15. This is about as hot as I would go in my barrel.

If you have have access to a chrono I would like to know what you are getting from 22 g.

In matches I use the 19 gr load to shoot active steel targets out to 300 yrds. It really smacks the steel pretty hard. I use the 19 g load because in a match I do not want to blow a primer and jam my gun... so I do not think that the extra 50-75 fps is worth the risk of a blown primer.

Your 22 g load should be a great deer load.

320pf

[Oldmanpaintball]

Will do, I am getting no signs of high pressure (yet) primers are a little flat. I was disapointed when reloadersnest got shut down. Always good data hanging around in there.


OMP

[Pitt300]

I ran into pressure problems @ 18.4 g H110 w/Model 1 Sales upper.
They are currently looking @ throat/leade.
Loaded them short to 2.050 (Nos BT) & 1.915 w Sierra 125g 30-30 bullets.
Blew a primer & had to beat open action.
Case mouths opened fine as I can easily insert a bullet in the fired cases.
17.7g shot great w/both.
Nos BTs just over 1 inch & Sierra 30-30s about 1.75.
I've only shot about 15 rounds thru it.
Had some loaded @ 19g but glad I didn't shoot.
Any suggestions?

[320pf]

I have had pressure high pressure signs with Nosler BT when I got to ~19-20 grs loads. When I changed to Sierra 125 I could get about 20 gr of H110 and th load shot fine. I then worked up a load using Speer 125 TNT and I got the same velocities with only 19 gr H110. I then tried 19.5 and 20 gr... the 20 gr blew primers so I went back down to 19 grs.

Last suggestion... try and get your hands on a chronograph. If you are getting between 2200 and 2300 from a 16-inch barrel with 125 gr bullets you are pretty close to the max.

The biggest thing that I have found is the seating depth. I had worked up a load that ran fine, but I had seated the bullet out to the maximum length to fit an AR mag. During the next reloading session I decided to seat the bullet about 2-3 mm deeper and blew primers with the same powder charge.

Also your barrel is new and the bore in still rough/tight as you shoot more rounds through it the barrel will smooth out and get better.


320pf

[Pitt300]

@ 17.7g w/H110 w/125g Nos BT @2.132" I got 2099.2 Avg fps - no problem
@ 17.7 w/125 30-30 Sierra @ 1.915 I got 2101.3 Avg fps - no problem
@ 18.4 w/125g 30-30 @1.915 I got 2184 Avg fps w/blown primer & stuck case
Couldn't find 125g Nos BT target w/18.4g H110.

All w/16" M1S upper-accuracy very acceptable.

320pf looks like you're right on. @ approx 2200fps I maxed!

Wonder if I seat bullets longer (if I can) will that lower pressures & let me get more velocity safely?

[Pitt300]

Oldmanpaintball,
Are you shooting a "true" JDJ 300 Whisper or a 300-221?
Are you shooting a AR upper or a bolt gun/single shot?
Think Sierra shows 19g max H110 @ 2000 fps out of 10" barrel w/125g Sierra SPT w/10" barrel.

[Oldmanpaintball]

You guys have me really curious. May have to pull a bullet and see what charge I have inside. I have a OLY 1-8 twist stainless.


More later


off to find the puller.

[Oldmanpaintball]

And that boys and girls is why you take what you here on the internet as fact. Fact is I only have 20 grains of H110 loaded. Sorry for the confusion.


OMP

[320pf]

Wonder if I seat bullets longer (if I can) will that lower pressures & let me get more velocity safely?

If you seat the bullet out a bit further the pressures will drop but so will the velocities. The trick is finding that "sweet spot" where the pressure peak is lower but you do not lose too much velocity.

Have you seen those pressure verus bullet/barrel travel plots that you can generate with QuickLoad? You are trying to lower the peak but spread it out over a longer period of time... If you move the bullet out too far the velocity will drop off.

I hope I have explained it clearly. They say a picture is worth a thousand word

320pf

[320pf]

I have been shooting 125 g Speer TNT with 19 g W296. This load is listed as a Max in the Sierra manual (of course with the Sierra 125 g bullet). I have chronographed this load many times in different weather/temp conditions and it always chronos at 2270 ±20 with a C.O.A.L. 2.082. (similar tomy H110 loads)

I loaded up 20 rounds using Speer 125 TNT with 20 g W296. The C.O.A.L. was 2.091. When I chronographed 5 shots of this load I got 2530 ±20 fps. At first I thought that my chronograph was not working. So I tested it with some 22LR from my Ruger 10-22 and they chrono'ed at 1100, like they always do. Then I chrono'ed 125 g Speer TNT with 19 g W29 and got 2250 close to what I always get with this load. So I concluded that the chrono was working fine.

I then shot two more five round chrono tests groups and got 2550 ±30 and 2540 ±20. The overall appearance of the primers is only slightly flatter than the 19 g load. Both loads also show about 1 in 5 primers with a slight cratering.

I did not have a chance to mic the heads to see how much the case heads are expanding... that is my next test. I would like to figure out if I can run this load on a regular basis.

These loads were all shot from my 16-inch 1:7.5 twist Noveske barrel. The gas port is in the the standard pistol position (not the Olympic arms pistol position). This is the first time that I have given my Noveske barrel a real workout. Most of my load development has been with my 16-inch 1:8 twist Olympic arms barrel.

The outside temp was 48 to 55 °F.

320pf