.300 Win Mag Die Set-up & to Crimp or not Crimp

[Heretoimproveforhunting]

I currently use a set of RCBS Competition dies to load my .25-06. My understanding is that the Competition seater die doesn't afford any kind of crimp (correct me if i'm wrong). I've had zero issues with the bullets on the rounds in the mag (Badger M4) shifting from firing, as this is a relatively low recoil round.

I've got a new build under way in .300 Win Mag. Magazine set-up will be the Badger M5. I get good results from my RCBS competition dies in my .25-06, so I went to look for the same in .300 WM. RCBS doesn't make them (at least off the shelf), so I stepped up to the Gold Match seater.

From what I'm reading the Gold Match seater doesn't crimp, but I've seen discussions about crimping or not crimping .300 WM. Do I need to seek out another die to set a light crimp on the .300 WM, or will I be fine without? Wondering what other people's experiences are with the round. I'm looking to load to the 2900 - 3000 fps range. Whatever the gun likes the most.

I've got Sierra 180 gr SBT Gamekings, 190 gr matchkings, and nosler 180 gr BT Ballistic tips that I wanted to test when working up loads.

From a die perspective, am I all set with the RCBS Gold Match 2 die set, or do I need to track down another die? I looked at the Redding Competition set, but it states that it doesn't crimp either.

 

[shoot4fun]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

If the major die makers are not making these dies with a crimp feature that should tell you how they feel about it. I don't crimp 300 WM and have never had an issue. BTW, I've been loading 300 WM for about 20 years off and on.
Congrats on the new build. If you need AICS mags for the M5 you can get them from Triad Tactical. They are not only a great place to deal with but a Snipers Hide supporter as well.

 

[ckruse]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

I'm in the same boat as the original poster. I'm planning on trying a Redding Taper crimp die, obviously done in an additional step. I've done this with .308 with good results. I set the die just to kiss the very edge of the case neck and provide a .002 taper crimp.

I certainly value the opinion of shoot4fun, as this is real world experience. I'll be running a 10 round AICS magazine at least part of the time, and don't like the thought of what might go on with those last few rounds in the mag under recoil. Probably not an issue, but I know Murphy all too well!

CKruse

 

[Rob01]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

I have never crimped my 300WM rounds. I use .003" of neck tension using bushing dies. I have never had any problems in 5 or 10 round AI mags.

I wouldn't crimp a bullet that doesn't have a cannelure especially match bullets but that's just me.

I haven't been loading 300WM as long as Shoot4fun has but have been for about 12 years now. I use heavier bullets in the 208-210grn range most time.

 

[ChrisGarrett]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

You need to 'know' how much neck tension your sizing die is placing on the necks of the specific brand of brass you'll be using.

If you're using brass with thin necks and getting only .001" of tension, then maybe you'll get some setback/lengthening with that stout chambering.

If you're getting .003"-.004" of neck tension, I wouldn't worry about crimping.

I don't crimp at all for my bolt guns and I shoot a 338LM. I do use bushing dies, however.

Measure a fired case to see where you are. Measure your neck walls carefully with a ball mic and double that number, then load a round and measure the necks and you'll have an idea.

Loaded round O.D. equals .334" at the neck, neck walls are .014" x 2 for .028". Bullet diameter is .308".

334"-.028"= .306 neck ID, neck tension .002 under .308" nominal bullet diameter"

For hunting and bigger calibers, to be safe, perhaps .003"-.004"?

For target shooting, we strive for .001"-.002".

Gas guns with large bolt carrier groups ~.004" should be fine to prevent setback.

My basic 223 FL sizing die puts about .004" of tension on most of the RP brass I reload for my AR-15. I took three loaded rounds and measured their necks and recorded this number.

I took each cart and chambered/extracted it three times from a magazine. Recording the numbers as I went along.

There was .001" and no more than .002" of setback after the three chamberings were performed.

Know what your sizing dies are doing with your particular brand of brass and crimping may not be necessary at all, even for gas guns!

Chris

 

[Heretoimproveforhunting]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shoot4fun</div><div class="ubbcode-body">If the major die makers are not making these dies with a crimp feature that should tell you how they feel about it. I don't crimp 300 WM and have never had an issue. BTW, I've been loading 300 WM for about 20 years off and on.
Congrats on the new build. If you need AICS mags for the M5 you can get them from Triad Tactical. They are not only a great place to deal with but a Snipers Hide supporter as well.</div></div>

I wondered as to whether it was needed, as the bullets are designed without a cannelure. Steve was actually the source for my DBM and AICS mags. Triad is great to deal with. . .

 

[Aimsmall55]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

I know that lee sells crimping dies. I have never used it, but the seater,neck,and full length dies are superb.

 

[woodspider]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">I have never crimped my 300WM rounds. I use .003" of neck tension using bushing dies. I have never had any problems in 5 or 10 round AI mags.

I wouldn't crimp a bullet that doesn't have a cannelure especially match bullets but that's just me.

I haven't been loading 300WM as long as Shoot4fun has but have been for about 12 years now. I use heavier bullets in the 208-210grn range most time. </div></div>

THIS ^^^ follow Robs advice and save hours of wasted time.
now In my Opinion and its just an opinion but born of experience THE .208 AMAX is the way to go for Long Range Target shooting. For hunting the .210 Berger is a good option and your drop chart will be really close to the 208 amax ballistics. They shoot about the same for hunting purposes/distances.
I wouldnt mess with the 180s. If you want to match the 190 FGMM just buy them its easier.

 

[Heretoimproveforhunting]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

novice question, but what are the 190 FGMMs?

I've had Sierra's work well in the past on my other rifles, but I guess it will really be up to the rig to determine once I get it and can shoot it. I had targeted the 180s and 190s as I can attain a drop that is almost identical to the drop of the 117gr rounds I'm tossing out of my .25-06 at around 3050 fps. I suppose my thought process was one where it would be a little easier to remember the drops between the two if they're close to the same. These will be my two preferred hunting rigs.

I'll take a look at the 208s.

 

[shoot4fun]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp




<span style="font-weight: bold">novice question, but what are the 190 FGMMs? </span>

I am currently using the 190 SMK bullet in 300 WM with excellent results. That said, I wouldn't use them for hunting.
Now, I am doing some testing with the new Berger 230 grain OTM Hybrid and it shows great promise in my 1 in 10 twist barrel.

 

[Rob01]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

I think he was speaking of the Federal Gold Medal Match(FGMM) 190grn 300WM load.

 

[shoot4fun]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

Same bullet. I've never tried the FGMM ammo in 300WM.

 

[ckruse]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

A lot of good advice here. I'm counting on using the 208 Amax, and H1000 like a lot of others. I acquired 500 rounds from the same lot just waiting on my build to finish. I'll have to look at the collet sizing dies. Sounds like the ticket. CKruse

 

[Rprecision]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Aimsmall55</div><div class="ubbcode-body">I know that lee sells crimping dies. I have never used it, but the seater,neck,and full length dies are superb. </div></div>

I have used plenty of lee stuff. Thier collet crimping dies and very well thought out and work great no matter the case length.

When devoloping loads for my 22-250, I too was curious about a crips affect on accuracy. I loaded up the same load, crimped a group and did not the others. I had less FPS spread with the crimped test group by around 25-40 fps.

Group size was about the same, the crimped ones shot a little better.

 

[Heretoimproveforhunting]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

Has anyone had any trouble loading the 208 AMAX using RCBS' Gold Cup series seater? I thought I read somewhere that people were having issues with that particular RCBS die on that bullet and the bergers, but that Redding's competition seater worked no problem. Can anyone confirm that?

 

[Heretoimproveforhunting]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bhanDallas</div><div class="ubbcode-body">Has anyone had any trouble loading the 208 AMAX using RCBS' Gold Cup series seater? I thought I read somewhere that people were having issues with that particular RCBS die on that bullet and the bergers, but that Redding's competition seater worked no problem. Can anyone confirm that?</div></div>

bump. any help with the last question?

 

[BuzzBoss915]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

The good advice here is no cannelure, no crimp. You may need bushing dies for the proper neck tension, and you may not?

The best way to go for me, is a Wilson die blank cut with the same reamer that your rifle was chambered with. I do not use any "comp" dies, I use straight line chamber type seating dies with an arbor press. For what it's worth. BB

 

[X-fan]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

Bullet tension will hold the bullet...I use bullet tension to control my 460G&A (500 grains at 2550 fps)...They never move.

I don't believe there is any way to crimp as accurately and repeatedly as we can control neck tension.

Peace

 

[freeflight]

Re: .300 Win Mag Die Set-up & to Crimp or not Crimp

I found this thread while researching whether to crimp 300WSM hunting ammo. In Lee's reloading manual, he went through great length to explain:
1. proper size case neck provided 0.001" neck tension
2. For bigger neck tension (>0.001"), bullet will expand the neck and bullet is a poor tool for that purpose. It may cause excessive bullet runout.
3. He recommend Lee Factory Crimp Die to crimp

Is this truth or fiction?