338 Edge

[Willy 1]

I had a 338 Edge built a while back and finally got out to sight her in today. The load that I used is 88.5 gr. H1000 behind the 300 gr Sierra hpbt match as I am fire forming the brass. I fired a couple of shots at the target from about 40 yards and thought the holes looked a little wierd so I walked up to check them out. The bullets had hit the target pretty much sideways or flat (keyhole). Has anyone else had this happen to them? My gun has a 26 inch barrell, with a 1-10 twist. I know that I am about 50 thosand off the lands,but would that cause this problem? Does anyone have any suggestions.
Thanks

 

[britz]

I guess I will just keep my nose out of this one /ubbthreads/images/graemlins/blush.gif

 

[Shawn Carlock]

I would check the twist rate to make sure it is a 1-10. You should be in the 2600 fps range and I have had no problems stablizing the 300 SMK at these speeds. I assume you have checke all the usual suspects, muzzlebrake alinement, square crown etc?

 

[davewilson]

for starters, you don't have to fireform brass for the edge.just push the necks out, load and shoot.

everything seems to be about right that you're doing. if i would venture a guess i would say go with more powder, not less. 88 grains might be too little and ignition might be suffering,making for very slow speeds. i shot 92 gr of H1000 last year with the 300 pills and 95 was still not too much. try 91 grs and use a crono. you should be at least 2600 and a 10 twist should stabilize that 300 just fine. let us know how you make out.

 

[Willy 1]

I checked and it is a 1-10 twist. It does not have a brake on it. Shawn does more powder sound like it could help. Dave I am a little nervous about shooting through my chrono. as the way they are coming out I could end up with a hole through something. Dave what does your gun have for a barrell length,mine is 26. Fireforming might be the wrong term, just the first time the brass has been shot after being necked out.

 

[Shawn Carlock]

I have run from 92-95 grains of H1000 as a final load depending on OAL and freebore lengths. Watch carefully for preasure signs and start working up. The Edge w/ the 300 SMK & H1000 seems to be one of those rounds that shoots better the faster you push it right up to max preasure. I have had several shoot their best groups with the bolt getting slightly sticky (unfortunatly this is not acceptable to me). I don't believe that velocity is the issue (it could be) I have down loaded the Edge to 1800 fps to test bullets at impact velocities and had no keyhole issues. Let us know how it goes.

 

[Fiftydriver]

I would have to agree with Shawn in that if your barrel is a 1-10 twist you should never see a problem with stability at any of the velocity range you should be using the Edge at.

Couple questions. I assume this is a match grade barrel that was new when the rifle was built??? Or was it a factory barrel rechambered to the Edge??

What I am getting at is if it was used, make sure the bore is completely free of copper and carbon fouling.

A good build up of either ahead of the throat can cause what you are seeing but I would say this is unlikely.

I also feel this is a mechanical issue. How did you measure your twist rate in your barrel. If I had to guess just reading the behavior of your rifle, I would say you have a 1-12 twist assuming everything else is set up properly.

Just curious how you measured your twist rate.

Like Shawn mentioned, check out the usual suspects, crown, brake and such.

If all checks out, I would seat those bullets to within 10 thou of the lands or even touching and drop back to 85 grains and work up from there.

One other reason for this may be that you have a loose bore. What brand of barrel is it if it is a custom pipe. I have seen exactly what Shawn has discribed many times with barrels with larger then nominal bores. They really start to shoot good at very upper end loads. The reason, in my opinion is that they need a serious kick in the rear to bump the bullet base up to fill the bore properly and this results in better consistancy and accuracy.

A bullet such as the 300 gr SMK has a relatively stout jacket and needs a good slap in the rear with high pressure to bump it up in a looser bore diameter.

This would be fairly uncommon with the top end match barrels but could happen.

If the upper end loads do not solve your problem, Just to prove the theory, get some 250 gr SMKs and see how they shoot. If they stay on point and the 300 gr SMK will not, I would almost bet you have a barrel that is not exactly 1-10.

BAscially test one thing at a time to eliminate it as a reason for the problem. That way you will be able to see exactly what effect each has on the rifles performance.

Keep us posted.

Kirby Allen(50)

 

[Willy 1]

Thanks for the replys
The barrel on this gun is made by Ted Gaillard. He is a very good barrel maker in this area very well known in the benchrest world. It started out as a 338 ultramag that I had converted over. It only had about 75 rounds through it before I converted it. It was very accurate as a ultramag.
The way that I checked the twist rate was with my Dewey cleaning rod. I put patches on it till I could just get it to go down the barrel. I marked the spot that I started from on the rod,also by the handle. I pushed it in till the mark at the handle was back to the top then marked the rod again and measured the difference. It was almost exectly 10 inches. I think this is a correct way of checking twist rate. I reloaded some of my brass last night starting lower going hotter and also made them longer roght into the lands.I will give this a try today, and keep you posted.

 

[Fiftydriver]

What bullet weights was it shooting well as a 338 RUM?

That should tell you close enough on the twist rate. Certainly accurate enough to tell if it is a 1-10 or 1-12 anyway!

I would doubt that seating the 300 gr SMK out into the lands will stop this but its worth a try. Not sure what to think really. Especially if the 338 RUM happened to be shooting the 300 gr SMK well????

Kirby Allen(50)

 

[Willy 1]

Well guy,s spent some time at the range today and the results were very good. When I reloaded this time I loaded a little hotter and made the oal 3.920 instead of 3.880. What ever the problem was was fixed is the long and short of it. The first rounds were at 89.5 grs seemed okay so I went up from their in .3 jumps up to 91.7 all with a oal of 3.92. When you guys said the velocity should be in the 2600 range you were almost bang on.
89.8 2672
91.1 2699
91.4 2726
91.7 2749
None of these loads showed any pressure signs so that is a good thing and I am happy with that load of 91.4. I fired 4 rounds of this load and had 3 at 2726 and 1 at 2726 so that is hard to beat.
Looks like this gun is going to be a shooter after all.
Thanks all for the help

 

[Shawn Carlock]

With your OAL you will probably presure up at 93 or 94 grains. You can also expect to run about 2800 fps or so. I am baffeled on your problem, I have run much slower with a 1-10 twist with no problems. At this point if it isn't broke don't fix it. Watch for the bullet to become unstable at distance when it slows down, it seems to me that this will occur for you at a given velocity reguardless of its location to the muzzle.

 

[Willy 1]

I only shot out to 200 yds today but the group was just under 3/4 of a inch for 3 shots. Nothing special but I was more interested in other things than group size. It will be getting the test at farther distances in the near future.

 

[downrangcounts]

Hi all,

I am new to the 338 edge. as a matter of fact, the rifle is not finished yet. I need advice on where to start reloading. 338 RUM or 300 RUM brass? Can I fireform 338 RUM in an edge chamber? Whose dies are recommended?

Thanks in advance!

 

[jwp475]

The 338 Edge is the 300 Rum necked up to 338 calibur with no other changes
No you can not use the 338 Rum case as it is shorter than the 300 Rum case