I am just getting ready to load some 200 gr. cast powder coated subsonics with 11.3 gr. 1680... I was going to use Remington 7.5 primers but they have been out forever... I just picked up some Federal Match small rifle primers... are they equally compatible w/o charge load change with the Rem 7.5?... Thanks
- Thread starter OutBack#1
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Officially no. Component change generally suggests a partial reduction of your load and rework up from there.
Now, many people just swap the primers and go with it, but if you're at the edge of pressure, small changes like that can easily lead to overpressure. For me, it depends how hot the loading is. Different lots of powder even, same kind, often requires tweaking of charge due to variation. L
All that said, why not knock a little powder off and work up again just to be safe if you are worried about swapping them and are asking us?
Now, many people just swap the primers and go with it, but if you're at the edge of pressure, small changes like that can easily lead to overpressure. For me, it depends how hot the loading is. Different lots of powder even, same kind, often requires tweaking of charge due to variation. L
All that said, why not knock a little powder off and work up again just to be safe if you are worried about swapping them and are asking us?
I am trying to stay in the subsonic range and still function in the 300 blackout without ejection problems... I ask because that is what this forum is about... Rather than to waste time and materials.
I don't see the caliber in the initial post but see you put 300blk in the response. Just a helpful tip would be to put as much info as you can in the first post. Rifle, barrel length, bullet, powder, running subs/supers, etc. I know you put some of that info but try to put it all in a concise form so guys can look at your situation with all details.
If you've been running rem 7.5's already and its good to go for you, then simply switching brands will most likely not cause an issue when you're running a reduced load like subsonics in 300blk. To be safe, I would reduce your charge by 0.5 gr and try the new primers, if nothing seems off, bump back up to your 11.3gr and make sure its good.
To be clear, switching primers doesn't always increase pressure. If 7.5's have you running ~1000fps, switching primers may actually bring you down a bit, so you might have to add a touch of powder.
Always just reduce to be safe and then work right back up. It only takes a few rounds to do the test.
I just bought a turret press and was given the load data by a friend... 7.5's have been unavailable for a couple months... a couple blocks of Federal's just became available... so I grabbed them.
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I am new to rifle loading/subsonic... done alot of shotgun loading... Thanks
There's no danger in swapping with a subsonic load.
Were it I, I'd load up 20 with the new primer and shoot them over a chrony, just to verify how close to 1080fps I was (and ensure pressure/timing is still consistent). If so, load as usual and proceed forward.
Were it I, I'd load up 20 with the new primer and shoot them over a chrony, just to verify how close to 1080fps I was (and ensure pressure/timing is still consistent). If so, load as usual and proceed forward.
Sounds good to me, glad to have another reloader! As a general rule of thumb, I tend to play it safe loading. Given your load, you have lots of wiggle room. However, there are plenty of subsonic loadings that are 1100 fps, but they are up there in pressure, and I'd not hazard a blind swap of components. A 247 cast .310 from a 300 blk bolt with a fast and quiet powder is easily full pressure, and simply doesn't have a lot of wiggle room.
So again, as a general rule, if you're unsure at all, back it off a little and check things. There is simply no reason not to.
If we are going into another shortage, there will be lots of swapping components lol... so make no mistake, im not advocating dont ask or dont do it! it's a sad day when you have to use titewad, red dot, and surplus pull down powder that's way too slow , but there are days like that.
So again, as a general rule, if you're unsure at all, back it off a little and check things. There is simply no reason not to.
If we are going into another shortage, there will be lots of swapping components lol... so make no mistake, im not advocating dont ask or dont do it! it's a sad day when you have to use titewad, red dot, and surplus pull down powder that's way too slow , but there are days like that.
