338 Lapua reloading question

[wbyfireman]

After almost 2 years of saving here and there I am having my first custom rifle being built in .338 Lapua. It will consist of McMillan A3-5, Bartlein 9.3" twist @27 1/2". Stiller TAC 338 action,Timney, Little Bastard brake.
So here is my dilemma/question to the more seasoned reloaders out there. My smith recommended a PTG and AI bottom metal/magazines which I purchased. I have purchased 300 gr Bergers, 300 gr Nosler CC, and 100 rds. Of the new Hornady 285's with the improved tips in order to test different bullets......

HOWEVER when I measured my magazine my max OAL will be 3.640" in order to fit. This is below the SAMMI recommended 3.681 min OAL for the heavier bullets. Is it safe to seat the bullets this far into the brass? I don't want to have to single feed (what's the point of a magazine system)!! I understand pressures increase faster the further the bullet is seated but is it safe to seat bullets this far in the Lapua brass to begin with??!!

Any help would be very much appreciated
Thanks to all and be safe

 

[RockyMtnMT]

After almost 2 years of saving here and there I am having my first custom rifle being built in .338 Lapua. It will consist of McMillan A3-5, Bartlein 9.3" twist @27 1/2". Stiller TAC 338 action,Timney, Little Bastard brake.
So here is my dilemma/question to the more seasoned reloaders out there. My smith recommended a PTG and AI bottom metal/magazines which I purchased. I have purchased 300 gr Bergers, 300 gr Nosler CC, and 100 rds. Of the new Hornady 285's with the improved tips in order to test different bullets......

HOWEVER when I measured my magazine my max OAL will be 3.640" in order to fit. This is below the SAMMI recommended 3.681 min OAL for the heavier bullets. Is it safe to seat the bullets this far into the brass? I don't want to have to single feed (what's the point of a magazine system)!! I understand pressures increase faster the further the bullet is seated but is it safe to seat bullets this far in the Lapua brass to begin with??!!

Any help would be very much appreciated����
Thanks to all and be safe

As long as you are not seating deeper than the ogive it will be fine. The bullet will take up some of your powder capacity and you may be jumping the bullet a bit before it engages the lands, depending on how your smith throated your chamber. Give it a go.

Steve

 

[wbyfireman]

As long as you are not seating deeper than the ogive it will be fine. The bullet will take up some of your powder capacity and you may be jumping the bullet a bit before it engages the lands, depending on how your smith throated your chamber. Give it a go.

Steve

I greatly appreciate the reply. Hopefully the new 285 GR hornadys Will arrive as expected at the end of this month I am interested to see how well they perform

 

[el matador]

I had the same dilemma with my 338-378 using the Berger 300s. The load data from Berger has the ogive into the neck about .100" which I thought was odd. I emailed them and they confirmed it was correct and would not cause problems. I just load them a bit under mag length and it works great. Seating depth will cause variation in your case capacity and pressure but if you're starting low and working up there won't be a problem.

 

[338edge]

After almost 2 years of saving here and there I am having my first custom rifle being built in .338 Lapua. It will consist of McMillan A3-5, Bartlein 9.3" twist @27 1/2". Stiller TAC 338 action,Timney, Little Bastard brake.
So here is my dilemma/question to the more seasoned reloaders out there. My smith recommended a PTG and AI bottom metal/magazines which I purchased. I have purchased 300 gr Bergers, 300 gr Nosler CC, and 100 rds. Of the new Hornady 285's with the improved tips in order to test different bullets......

HOWEVER when I measured my magazine my max OAL will be 3.640" in order to fit. This is below the SAMMI recommended 3.681 min OAL for the heavier bullets. Is it safe to seat the bullets this far into the brass? I don't want to have to single feed (what's the point of a magazine system)!! I understand pressures increase faster the further the bullet is seated but is it safe to seat bullets this far in the Lapua brass to begin with??!!

Any help would be very much appreciated����
Thanks to all and be safe

Another option would be to have your smith install a wyatts extended mag box.

 

[wbyfireman]

I had the same dilemma with my 338-378 using the Berger 300s. The load data from Berger has the ogive into the neck about .100" which I thought was odd. I emailed them and they confirmed it was correct and would not cause problems. I just load them a bit under mag length and it works great. Seating depth will cause variation in your case capacity and pressure but if you're starting low and working up there won't be a problem.

Thanks for the reply

 

[wbyfireman]

Another option would be to have your smith install a wyatts extended mag box.

Problem Is I already have 400$ invested the PTG and AI mags. If they don't work out then I have no choice but I will keep my fingers crossed they do!!

 

[wbyfireman]

I had the same dilemma with my 338-378 using the Berger 300s. The load data from Berger has the ogive into the neck about .100" which I thought was odd. I emailed them and they confirmed it was correct and would not cause problems. I just load them a bit under mag length and it works great. Seating depth will cause variation in your case capacity and pressure but if you're starting low and working up there won't be a problem.

What type of results are you getting? FPS, moa, etc. just curious with the 338-378.
Thx

 

[el matador]

I haven't finished my load development with the 300s yet. I started with H1000 and only fired about 12 rounds. It performs ok...around 2800 fps and groups 3/4 moa. Never pushed it to max load though I was probably close. I already have a 1/2 moa load with H1000 and 250 Accubonds going 2975 that's comfortably below max for long brass life. Once I read about RL33 in this cartridge I abandoned my load development for the 300s with H1000. I got my hands on some RL33 and have my first batch loaded up and ready to shoot. Hoping to get north of 2900 with an accuracy load. I've heard people are getting up around 3000 fps with this powder and a 26" bbl although I'm sure that's a fairly toasty load. I like to back off max by at least a couple of grains since brass is $3 per.

I'm shooting a factory Accumark that's bedded with a trigger job. It's not as accurate as many of the custom guns out there but it's at least a 1/2 moa gun based on my testing with the 250 Accubonds. Easy to find sub-moa loads with the 3 bullets I've tried. If I can get the 300s shooting 1/2 to 3/4 moa at 2900 fps I will use that for my long range elk load. I'm also thinking of loading some 210 partitions really light so I can hunt without the brake at closer range. For a longer shot I can attach the brake and drop in a 300 grainer.

 

[wbyfireman]

I haven't finished my load development with the 300s yet. I started with H1000 and only fired about 12 rounds. It performs ok...around 2800 fps and groups 3/4 moa. Never pushed it to max load though I was probably close. I already have a 1/2 moa load with H1000 and 250 Accubonds going 2975 that's comfortably below max for long brass life. Once I read about RL33 in this cartridge I abandoned my load development for the 300s with H1000. I got my hands on some RL33 and have my first batch loaded up and ready to shoot. Hoping to get north of 2900 with an accuracy load. I've heard people are getting up around 3000 fps with this powder and a 26" bbl although I'm sure that's a fairly toasty load. I like to back off max by at least a couple of grains since brass is $3 per.

I'm shooting a factory Accumark that's bedded with a trigger job. It's not as accurate as many of the custom guns out there but it's at least a 1/2 moa gun based on my testing with the 250 Accubonds. Easy to find sub-moa loads with the 3 bullets I've tried. If I can get the 300s shooting 1/2 to 3/4 moa at 2900 fps I will use that for my long range elk load. I'm also thinking of loading some 210 partitions really light so I can hunt without the brake at closer range. For a longer shot I can attach the brake and drop in a 300 grainer.

Very nice, I just dropped off all on my "parts" to the gunsmith yesterday. This will be my first custom rifle. I will post some "gun-porn" of it when I get it finalized!!

 

[el matador]

Very nice, I just dropped off all on my "parts" to the gunsmith yesterday. This will be my first custom rifle. I will post some "gun-porn" of it when I get it finalized!!

Can't wait to see it. Good choice on the parts, sounds like a great build. I wish my big 338 had a longer barrel but when you buy factory guns you don't get much of a choice. 27.5" sounds great for a Lapua. I bet you get excellent performance out of that gun since you can run the brass a little harder.