Actual lapua velocity

[backyardsniper]

I'm debating between building a regular lapua or improved. It seem that seekins 3.9 DBM is non existent so my question is what velocity should I expect with the 300 otm from a standard or lets say cip mag at 3.7 oal in a regular lapua vs what i can get from a improved lapua if I run it as a single shot. It is cheaper to build it as a single shot since I don't have to buy bottom metal but that will be offset by having to buy specialty dies so it is the same either way as far as cost. I already have standard 338 lapua dies. I have to figure it out soon because I have to order the stock and tell them what to inlet it for.
Does the improved bring enough extra performance to justify making it a single shot or can I get 2800-2850 with a mag fed standard lapua with the following specs?
I do love having the back up shot in the rifle not to mention being able to carry the rifle with a loaded mag and empty chamber.

Stiller tac 338
27 or 28" broughton 5c rem varmint/sendero contour
Manners t5 elite carbon fiber

 

[barnesuser28]

With RL-33, Lapua brass, and 300 grain berger OTM from a 26" savage barrel i am getting 2832 fps based on my magnetospeed, seated to fit the 3.760" mag. With a 28" barrel and a little more powder (i can go a grain heavier) you should have no problem getting 2850-2900 fps from the standard Lapua.

 

[backyardsniper]

Thanks that is what I need to know. now I just got to figure otu which bottom metal. what bottom metal do yall recommend for AI cip length mags

 

[pwrdbycotn]

Have you looked at the 3.9" wyatt's mag box? I just had a 300 RUM built and used this box and it works perfectly. You would have to talk to your smith about the action mods that would have to be done and whether he would be willing to do them but that might work well for you. It would also be lighter than the seekins dbm. I have the seekins dbm on my lapua improved and it works fine, but it's way heavier than a bdl setup.

 

[Broz]

I recently built a 338 Lapua AI using a Stiller 338 single feed. I would do it again in a heart beat. With a 30" Hart I got right at 3000 fps with 300 Bergers and 100 gr of VV N-570

I think it is safe to say you can look for 150 + fps from going AI Lapua. Great round!!

Jeff

 

[backyardsniper]

Yeah broz. I ditched the 30-378 idea and I bought a stiller tac 338 today. Would you recommend single feed over magazine and if so would you have the stock made like an adl not a bdl with floor plate. What shoulder do you recommend and where do you go to get the dies made

 

[Broz]

Yeah broz. I ditched the 30-378 idea and I bought a stiller tac 338 today. Would you recommend single feed over magazine and if so would you have the stock made like an adl not a bdl with floor plate. What shoulder do you recommend and where do you go to get the dies made

Yes I would single feed. I always do anyway with a long range rig. While prone one in the chamber and one on the ground should do it and only takes a second to reload if needed.

Yes on the ADL style. Leave the strength in the stock and this allows a good bedding area.

The easiest reamer to use will be the 40* 338 AI from PT&G. Then just call Redding and they make the dies for the PT&G 40* 338 AI. If you get lucky they may even have some on the shelf. That was how I got my last ones.

Jeff

 

[dkhunt14]

You should get 100 to 150 more with the Lapua IMP. Length of case will be about the same. It all depends on throat for OAL but if you throat it short you may have a pressure problem or have the pressure ring of the bullet behind the neck shoulder junction. Talk to Kiff about what bullet you want to shoot. I am shooting my IMP with RE 33 and 300 Berger Elites. I just slowed them down to 2993 and it hammers there. Matt