Sierra 55 Blitzking Profile

[Derral Crance]

I have worked up prairie dog loads for my 22-250 and 220 swift using Sierra .224 55 grain blitzking bullets. Purchased a box of 500 to load and discovered the profile of the projectiles are different than my original bullets. The length increased by .014, the dimension from base to ogive decreased by .016 and the diameter changed from .2250 to .2235. Has anyone else seen changes like this in Sierra bullets? I would like to get 500 to 1000 bullets like the originals.

 

[Seabeeken]

Good catch. This is why I always measure. I found that Hornady had changed some of their XTP bullets a while back. I noticed the loaded round didn't look like the older bullets. Upon measuring I found the nose was longer and the bearing surface shorter. Perhaps for better feeding. Ive measured ever since

 

[orkan]

Pretty common with all manufacturers. This is why buying in large quantities of matching lot number is important.

Dies wear out. Jackets change. Bullets from lot to lot almost universally vary. Some vary a lot, others don't. Just depends on how well the operators are managing the equipment.


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[ShtrRdy]

That sounds pretty extreme. Especially for the diameter. I would call Sierra and see what they say.

 

[Doom2]

Actually a 0.225" diameter would be out of spec and 0.2215 would be SAAMI minimum. Sierra may have tighter specs.

 

[Derral Crance]

Doom2, thanks for the post. You are correct on the diameter. I had not checked the SAAMI specifications. My concern is still the profile that is much different than the bullets I've been reloading. I'll have to start all over to work up loads for my two rifles if the accuracy changes. I'm sure the least I'll have to change is my COAL.

 

[Doom2]

I'm curious, you refer to COAL. Are you setting cartridge overall length? It's usually better to seat cartridge base to ogive and I suspect your real bullet base to ogive difference is overestimated, especially if your using a Hornady gauge. They use the same insert for both 20 and 22 caliber.

You should not need to do a complete work up if you have a good powder node. At most you should only need a seating depth test.

 

[Derral Crance]

Doom2, your right again. I have been using the Hornady gauge. I just loaded two groups of test rounds with the powder charge from original loads. Used the COAL since it's easier than measuring the base to ogive. The theoretical seating depths result in .015 and .020 jump. If they shoot in the 2's or 3's I'll load for prairie dogs. The deeper I get into this reloading I find the less I know. I'll keep you posted when I shoot the test loads. Need to get to the range when there aren't AR 15 and 50 cal shooters??? THX--Derral--

 

[Rflshootr]

Also, bullet manufacturers redesign occasionally to try to get the B.C. higher. A longer nose is one way of doing that which means to keep the same weight, the material has to come from somewhere. Either in the ogive, the bearing surface or both. May have been why you're seeing the change. The trend in shooting is more toward long range. Lots of shooters look at B.C.'s from different manufacturers to decide on which bullet to use, many times picking the higher one if their barrel twist will handle it.