Sierra 168 Match King Crimp Question

[Dane R. Marley]

I am planning to load some Sierra 168 Match King bullets. Should I perform a crimp? I will be shooting these reloads from 3 Mag fed rifles and a belt fed rifle.

I have a Lee Crimp Die and I also have a Redding Taper Crimp Die that came with my Redding 308 3 Die Set. I am thinking a slite taper crimp using my Redding Crimp Die would be best if I do do a crimp.

Your thoughts and suggestions will greatly be appreciated.

Dane

 

[AJC1]

No crimp...

 

[Nature Boy]

I don’t think it’s necessary as neck tension is usually sufficient to maintain bullet position in the case. Your belt-fed application might be the exception as the rounds are subjected to more repeated recoil forces.

With that said, the only thing a slight crimp will be detrimental to is accuracy so if that’s not an issue then crimp away.

 

[AJC1]

I am planning to load some Sierra 168 Match King bullets. Should I perform a crimp? I will be shooting these reloads from 3 Mag fed rifles and a belt fed rifle.

I have a Lee Crimp Die and I also have a Redding Taper Crimp Die that came with my Redding 308 3 Die Set. I am thinking a slite taper crimp using my Redding Crimp Die would be best if I do do a crimp.

Your thoughts and suggestions will greatly be appreciated.

Dane

Why would you use a smk in a belt fed gun...

 

[dredd]

I do not crimp for any of my "normal" auto loaders. (AR10 variants & M1A's)

I honestly don't know enough about a belt fed rifle to comment.

 

[Dane R. Marley]

Why would you use a smk in a belt fed gun...

The OOW M240 is a sub MOA rifle with Match Ammunition. I plan to reload match grade ammunition and see how well it does at my range in New Holland Pa., 25 yrds - 700 yrds. I am also planning on reloading some 178s in the very near future. The only powder that I have right now is 8 lbs. of IMR 4895. I plan to acquire some additional powders that will tighten up my groups.

I am getting 1" groups at 100 yards with standard Federal M80 ammunition.

I have an Eotech VUDU 5x25 scope mounted on my M240. I will be using my OSS HX-QD 762 Ti on my 240. I had to get an adapter made since the M240 thread pattern was non-standard.

 

[AJC1]

The OOW M240 is a sub MOA rifle with Match Ammunition. I plan to reload match grade ammunition and see how well it does at my range in New Holland Pa., 25 yrds - 700 yrds. I am also planning on reloading some 178s in the very near future. The only powder that I have right now is 8 lbs. of IMR 4895. I plan to acquire some additional powders that will tighten up my groups.

I am getting 1" groups at 100 yards with standard Federal M80 ammunition.

I have an Eotech VUDU 5x25 scope mounted on my M240. I will be using my OSS HX-QD 762 Ti on my 240. I had to get an adapter made since the M240 thread pattern was non-standard.

View attachment 1136187
View attachment 1136188

I have never loaded for a belt fed so I retract my statement in that area because I am unqualified to discuss that.

 

[Dane R. Marley]

I do not crimp for any of my "normal" auto loaders. (AR10 variants & M1A's)

I honestly don't know enough about a belt fed rifle to comment.

I am worried that the bolt slamming home on the 240 may push the bullet forward. I can do a test like I do with my revolver reloads. I can mike the rounds at the range, charge the action, then eject the unfired cartrigde and mike it again. If the bullet moves forward I will then try a slite taper crimp on my reloads.

I did put a very slite crimp into the cannelure on the Hornady 150s that I reloaded this AM. I loaded 3 different loads, 20 rounds each, for a ladder tests.

 

[Blue68f100]

I am worried that the bolt slamming home on the 240 may push the bullet forward. I can do a test like I do with my revolver reloads. I can mike the rounds at the range, charge the action, then eject the unfired cartrigde and mike it again. If the bullet moves forward I will then try a slite taper crimp on my reloads.

I did put a very slite crimp into the cannelure on the Hornady 150s that I reloaded this AM. I loaded 3 different loads, 20 rounds each, for a ladder tests.

View attachment 1136204

I load for a AR-10 in 6.5CM. I do not crimp at all. What I found is if yo keep the neck tension at a min of 0.003"+ 0.004" your good.

 

[Charlie98]

I am worried that the bolt slamming home on the 240 may push the bullet forward. I can do a test like I do with my revolver reloads. I can mike the rounds at the range, charge the action, then eject the unfired cartrigde and mike it again. If the bullet moves forward I will then try a slite taper crimp on my reloads.

Understand the forces that would set a bullet back are different between manually cycling an action vs the action under fire. You might put a live round as round #1, then a dummy at #2... so the #2 round will see the full force of the action cycling.

 

[Charlie98]

I did put a very slite crimp into the cannelure on the Hornady 150s that I reloaded this AM. I loaded 3 different loads, 20 rounds each, for a ladder tests.

The Hornady 150grn FMJ isn't a bad bullet... it's a lot better than many FMJ's, but if it's the bullet I'm thinking of, the cannelure is quite high for a .308, so watch your pressures.

L to R: Winchester, Prvi, Hornady...

 

[Walkalong]

The Hornady shoots well for a FMJ.