I have an issue thst has been driving me nuts lately. When seating .30 cal SMKs, I load to the max length of my FN SPR's internal magazine, or 2.840". Anyway, due to meplat inconsistancy, I am constantly adjusting my seating die to keep COL the same. I know that doing so breaks the consistency rule. I am thinking about getting a Sinclair meplat trimmer to address it, but in the mean time I was wondering how most people set their seating die. Do you adjust for a certain COL and leave the die alone not worrying about the potential ten thousandths or so difference between rounds? Thanks in advance.
- Thread starter One Holer
- Start date
Get a comparator.
Sort your bullets by base to ogive measurement, and then measure your COAL from CH to Ogive and ignore the meplat unless they no longer fit the magazine.
Sort your bullets by base to ogive measurement, and then measure your COAL from CH to Ogive and ignore the meplat unless they no longer fit the magazine.
+1 to asperly, Im not sure what sierra you are loading but factory 168 gmm Is jumping in my rifle about .050 and it produces a 1 hole group at 100 yds. I haven't tested a lot of sierras but have read that they are not as sensitive to seating depth like some of the bergers I load. Have you tried several distances away from the grooves to find best accuracy?
Ditto... Get a comparator
I've also noticed Sierra's to be jump tolerant. Well, except for my .243 with Retumbo using 107 gr SMK. It likes to be jammed.
I have 500 sierras that ranges from .650 to .690 ogive to base. I was fucking around with my seating die like you are until I finally sat my ass down and separated the bullets into groups (.650-.655 in one bag, .655.5-.660 in another and so on) Once all the bullets were separated I was able to set my seating die at the desired length per group and reload without constantly changing the length. +1000 on the comparator. Its one of those things you have to have.
IME Bergers are MUCH more consistant than the Sierras. After sorting 800 SMK from the same lot I had 4 different batches. After sorting 1500 Bergers from the same lot I only have 2 different batches with 11 oddballs.
My experience as well. Hell even the cheap amax is pretty darn consistent. After shooting some awesome groups with the 178 amax it's all I use in my .308 round. I like that it can be used for hunting. Mine didn't shoot great until I seated them deep. 2.79" or less
But to answer your question you'd need a comparator or switch bullets. If I were you'd I'd start with amax. They are dirt cheap shoot well and are effective against game. What's not to like? If they don't work for ya try the smk, Berger, etc. unless you have a specific goal in mind already (ie highest Bc, subsonic, etc).
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Whats your favorite load with the 178 Amax?
Took me forever to perfect it but it was
178 amax
43 gr 4064
Fgmm brass
Cci br4 primers
Seated to 2.79"
Shot about 4 round group .3-.4 moa.
I will be switching to lapua brass now and due to supply switching to winchester primers. I doubt I'll see any difference. If anything groups might get tighter With the better brass.
This was out of a 16" dta.
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Good to know. That's the same powder charge I used to create a bug hole @ 100 yards with Lapua brass, CCI BR primers and SMKs.
My bullet seater (rcbs, Lee) seat the bullet about an 1/8"+ down from the tip. Once my ogive length is set using my comparator (GET ONE!) my dies will seat consistently within .001 measuring the ogive. Tips may very but I don't measure those much anymore. The SMK, Amax in different calibers all seat consistently. I don't measure base to ogive length, any difference will be pushed into the case. The "jump" will be consistent an this works in several different rifles of different calibers with different weight bullets producing consistent 3/4- sub 1/2 moa accuracy.
My point was that a die that seats based on ogive would essentially seat every bullet to the same amount of jump or jam regardless of minor differences or even manufacture. Basically a comparator built into a seating die.
Most seating dies contact the bullet pretty close to the ogive, not at the tip. If it's contacting the tip then you need a different seating stem. You shouldn't change the seating depth to keep the OAL the same, it's the position of the ogive that's important in determining the distance to the lands. Once you get your seating die set up with your desired seating depth then ignore the cartridge OAL and seat all of the bullets using the same setting of the seating die, the position of the ogive should be the same amongst them all. Trying to make the OAL the same for all of them results in varying ogive positions and that's not good. Matchkings are about the worst for giving different OAL's, they shoot great but the tips are really inconsistent. A bullet comparator is a nice tool to have when dealing with matchkings.
+1. Very good idea. I could make a seater stem with the reamer that was used to chamber the rifle. Hmmmmmmmm.
Paul
Unscrew the seater stem and look at it. Stick a bullet up in it and see if it is hitting the tip before the ogive. Just recognize that seating stems and bullet meplats come in various sizes and occasionally, they are not compatible.
If you need to, get some titanium epoxy and custom mold the stem with the bullet. BB
If you need to, get some titanium epoxy and custom mold the stem with the bullet. BB
Why the fuck don't companies do this? It makes the most sense. Is it because some bullets will vary greatly in thickness even if they are the same grain and the ogives will be different? Group buy Boltfluter? I'll take it!
After thinking about this, the only fly in the ointment would be if the reamer that your barrel is chambered with has a different lead angle, which would change the point where the seater is tangent to the bullet. Still this is a great idea and something to think about. Most reamers have a 1.5 deg. leade so this may not be that much of a problem and would probably be correct for 95% of the rifles out there. It would be cool to take a Redding die with the floating sleeve and run a reamer into it and see what happens. I believe it would work. Hmmmmm. LOL.
Paul
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Maybe it makes sense to you guys but it makes absolutely NO sense to me. How in the hell are you going to fabricate a seater stem with a a chamber reamer? BB
There isn't just a difference in ogives (secant vs tangent) of the different bullets but also within the type of ogive for a given caliber. Look at the difference a .264 cal 160 gr round nose, 140 amax, 126 gr scenar, 123/ 140/142 SMK, 125 b-tip and on an on an on. They all have a slightly different profile and definitely different lengths from base to ogive to tip. One could always have a custom seating die made to a specific bullet profile, but why?
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I've been having good consistency measuring the ogive to base of cartridge using the digital headspace gauge from Larry Willis anyone else use this tool?
I have other products of his. He makes good products.
You have my blessing to run with it and make trillions of dollars. All I ask is you send me one.
Doesn't really matter what ogive shape you have. As long as you have the clearance for the tip, it will seat every bullet where it would be tangent with the leade in. Hope that makes sense.
Paul
You have my blessing to run with it and make trillions of dollars. All I ask is you send me one.
I like the sound of trillions!!
Paul
