Chasing speed - am I being greedy?

[novaman64]

So finally got some spare time with work slowing down (got a new job I start after turkey day) plus the rains put a dampener on my shop project, and with the addition of my new Lyman DPS 1200 Ive been reloading and developing some loads for a couple rifles. Lately have been concentrating on my Tikka T3 Lite 7 mag. Tried a couple different powders, but have had best results with H1000, I have been using my Berger 168 VLD's with a standard primer, and just cheapo Winchester brass.

Anyways, most accurate load I have had has been 68.5 grains of H1000... See pic...

Anyways, been doing ladder loads. Started down at 66 grains, most accurate was 68.5, when I hit 69-70 it start getting pretty wide (1"), and the most powder I have put through it so far is 71.0 grains of powder. Dont have any pressure signs yet, and the groups are starting to shrink back down (71.0 was at .632"). So should I keep going hotter to see if the groups get better, or leave it at 68.5 grains? Looks like most guys on soe other boards that are running the same bullets and powder are right around the 72 grain range getting between 2900-3000 FPS...

Out of a 24" barrel how much velocity is an extra 5 grains of powder going to give me?

 

[ICANHITHIMMAN]

What range are you testing at? Try a CCI BR2 Primer with both of the loads you had good results with.

 

[novaman64]

100, gonna go out to 200yrds next trip out.

Debating if I should try more powder...

 

[ICANHITHIMMAN]

100, gonna go out to 200yrds next trip out.

Debating if I should try more powder...

Well it has been my experience that there can be a very large difference in a group that looks amazing at 100 yards and what it does at 200 yards, just keep that in mind. As long as you don't have pressure signs it sounds safe and you should explore your options if your not happy. The CCIBR2 seams to be a load tamer, making H1000 more consistent.

 

[submoa]

am i wrong of shouldnt you use mag primers in the 7mm mag ??????

 

[dbhostler]

am i wrong of shouldnt you use mag primers in the 7mm mag ??????

Depends on several things. I use non mag primers in my 300 RUM with RL 25, but this is with a 30+ inch barrel. I would probably stick with mag primers. You also need to hook up with a chronograph. Only then can you tell what velocity your round is producing along with checking for pressure signs as you approach max.
db

 

[rick523]

I use 68.5 grains of H100 in my 7mm, CCI250 primers and it's going 2932fps this is group I shot Sat. 800yds. measured just over 2.75" with the cold bore shot at the right, 5 shots. The only thing I should have done is checked pressure didn't have meter with me so used standard pressure actual pressure would have put them up where they should have been. I could get more speed but why make it harder on barrel. Barrel is 28".

 

[Derek M.]

To the OP, I always like to see what safe max of powder is in all of my rifles, so keep stuffing. When you find out what the rifle will take, back off maybe a grain, grain and a half, then start monkeying with seating depth. That's my preferred method, though, it doesn't always work.

As to primers, I've heard and read where some guys get great results by using regular primers in magnum cases due to a "slow start" and an "even burn up the column." I've also heard that once you have a case that has 60 grains of powder, it's time to try a mag primer.

I've used magnum primers in smaller cases like a 270 and have had great results. I've never entertained using a standard primer in a mag case. I have no plans to do so.

 

[Derek M.]

delete

 

[Joe King]

I haven't tried Br2 primers, but 215M consistently sucks things right down in my 7mag.

You might want to take a 2nd look at 70-71gr gr if you do try Fed match primers. that's where I'm runnin it at, as for being hard on the barrel, just keep the barrel cool, 7mag isn't over bore enough to have a short barrel life if you don't let get past luke warm. Besides a shot out barrel just an excuse to get a really good one

 

[backwoods83]

I have got close to 3200fps with 73grns H1000 in brass (win) that had several firings on it using 162amaxs touching the lands in a 24" pipe with no pressure, groups were good, but I tried 210 and 215m primers, and br2s and 250s, but the es was horrible. I ended up with 67.5grns H4831sc and 210Ms in fed brass for 3032fps avg 12fps es, 3/8moa or smaller, give it a try, start at about 64grns, somes accuracy and es fall off bad with H1000 and 24" barrels.

 

[D.ID]

I use mag primers for magnums and standard primers for standard cartridges......Has worked out real well. I learned the hard way that shooting groups at 4-900 yards answers more important questions than the chronograph ever did. For me personally: I do not care what max is, If I can repeatably stack em on each other at 800............I am done developing my load........... If my chrony says it is fast, slow or perfectly consistent with an ES of 3fps.............none of it matters If I can't hit my target. If you have the accuracy you seek and you brass is holding up.................. be happy and shoot. My .02

 

[rick523]

I use mag primers for magnums and standard primers for standard cartridges......Has worked out real well. I learned the hard way that shooting groups at 4-900 yards answers more important questions than the chronograph ever did. For me personally: I do not care what max is, If I can repeatably stack em on each other at 800............I am done developing my load........... If my chrony says it is fast, slow or perfectly consistent with an ES of 3fps.............none of it matters If I can't hit my target. If you have the accuracy you seek and you brass is holding up.................. be happy and shoot. My .02

+1 Could not have said it better.

 

[backwoods83]

I guess the answer best suited would be there is absolutely nothing wrong with chasing velocity if all else remains the same! As for primers, it is better to match the heat of a primer with the type and charge weight of powder being used, not by the size of the case or what it says on it, for instance I use WLRP or mag primers with almost all ball powders because of a cleaner more consistant burn, or if its not 20* or colder out and I'm using 4350 in a 300 wm or wby I use standard primers for consistancy because Imr and H 4350 are easy to ignite, I do not care if it says mag on the case head. Just some random thoughts.