308 reloading. bullet seating and OAL.

[vujade]

Hi guys,

Can I pick your brains...

Reloading for a Savage 10fp in 308. 20 inch barrel.

With Factory loads (Hornady TAP/FGMM), I average .5-.75 inches @ 100 yards.

Shooting off a stable platform of sandbags in the front and back.

Reloading on Fed cases. Winchester primers. Varget powder. 168 Hornady Amax and 168 SMK. Cases trimmed to 2.005. OAL 2.800.

My first reloads (forgot to trim but the cases were under 2.015) netted 3 shot groups in the .4-.7 inch mark. A slight improvement over the factory. I only tested powder weight from 42-43.5 (.5 increments) but the 42 grains of Varget seemed to have the smallest deviations/groups.

Just recently, I got a hold of a tool (someone was helping me so I don't know what this is called) but it used a once fired case and the calipers to measure where the bullet meets the rifling/lands (!?). Any, that tool said to increase OAL a bit. We started conservatively. In the end, the cases were 2.875 (averaged since the tips of the bullets were not all uniform).

Using a 42 grains and cases OAL at 2.875... I was disappointed that all the shots were .75-.9 inches. (I shot 7 groups (3 for SMK, 4 for AMAX).

I plan to dial it back to make them shorter but I had thought it would have made things better. Is there something I missed? As a test, I had 3 rounds from my 'last' batch where they rounds OAL were 2.800 can it made a clean .500 group.

I plan to make some more rounds of a the shorter variety but I'm open to some comments/advice/etc.on any thing else that may cause this/ways to make the groups shrink. (the only other factor was that I trimmed the cases this time)

I just want to make some 1 ragged hole groups like I see on the internet. =)

[smopoim86]

When you change the length, you are also changing the pressure some. I'm definitely not an expert here, but you are changing more than the jump to rifling when you change the oal.

You should shoot them across a crono and see how the velocity changes with the oal.

[gregintenn]

Some of my rifles shoot better with the bullet seated where it touches the lands when chambered, while others shoot better with a deeper seated bullet. I find no rhyme or reason for it. I suppose it's just a difference in the particular guns. You'll want to try loads with progressivlely shorter to longer OAL's, just as you tried loads with different powder charges.

A 1/2" group is nothing to sneeze at. If you keep at it, you'll likely shrink your groups, but you'll put in a lot of effort for very little gain. But hey, that's part of the fun of reloading.

Another thing you might want to try is a flat base bullet. I often find that boattails sometimes do not stabilize well until out past 100 yards.

[vujade]

thanks for the advice guys.

I had just assumed closer to rifling = better.

I'll also look into a flat base bullet.

so many options/conditions/combinations with only millimeters at stake! You'd think it would drive one crazy but it's so much fun.

Edited June 21, 2012 by vujade

[Jonnin]

If you are only going to be shooting it at 100 yards, you can try a very wide variety of loads --- you can easily go from 50% of the starter load data all the way up to the max. You may find that a reduced load shoots better in your gun at the shorter ranges, or not, it can vary. I have had really good luck with reduced loads on boat tails in my 308.

Another issue is the human factor and setup. If you have perfect ammo, what sort of group can YOU make with that gun and setup realistically? The setup matters too: 1/2 inch group at 100 is impressive if you have iron sights or a 4 power scope. Mine has a 24 power scope and at 100 yards a dime to me looks bigger than it does in my hand (ok, maybe not, but you get the point). What I am saying is that it is very possible that your ammo is already capable of putting all the shots in one hole, but your optics or ability is not, or other factors such as a hot barrel come into play. I do not know a thing about you so I can armchair quarterback here.... all I am saying though is that before you spend the next 4 years of your life trying to perfect the ammo, make sure the ammo is actually the problem at hand.

I am passing good with a bench rested rifle. Not great, but decent. I doubt I could put all the shots in one hole with only 3 shots on a regular basis. I could probably DO it, so long as I do not have to show you the 5 or 6 other targets where they were NOT all in the same hole, see? The internet is great that way... I do not have to show you my fail targets. Even with my stupidly overpowerful scope, it is a difficult goal.

Edited June 21, 2012 by Jonnin

[vujade]

I appreciate your comments Jonnin.

For the first year of owning the rifle, I thought it was a dud because all forums said how Savage rifles should be making 1 hole groups and all I could muster was a slightly less than half inch at 100 with FGMM/Hornady TAP. Reloading threads on forums likewise was starting to set my expectations too high.

To answer your question - it's a Nikon 14x40 scope and I know there is some human error as well since even with sandbags, I know I can't be aiming at the exact dot every single time and I only allowed a few seconds to let the barrel cool between shots (although after each 2 groups, I cleaned the bore and rested for 3 or so minutes. I know the barrel was hot but perhaps over estimated a bull barrel.

I also purchased the rifle used. (it's an older Savage 10fp pre-accutrigger). Is it unreasonable that a barrel could be worn out? (I can certainly see the rifling but what is a true test?) I never thought of that.

I've only tried loads from 42 to 43.5. I need to try some lower powered ones and give it more time.

[leroy]

vujade: RE: Your concern. "... Is it unreasonable that a barrel could be worn out? (I can certainly see the rifling but what is a true test?) I never thought of that. ....". ---- The barrel aint worn out. This rifle is shootin pretty good for an off the shelf rifle. Like mike says; sometimes there aint any ryme or reason to lots of this stuff. You just have to experiment a bit.

Several years ago, i spent a pretty good amount of time shootin a Ruger M77V (...heavy barrel...) with a 12 power lyman.

Did the whole thing with the brass and 168 grain match bullets. Five shot groups in the .5 to .75 range. I think anything hovering around .5 with a "medium kicker" like the 308 is pretty good shootin for country boys usin off the rack rifles. I'll freely admit that my experience is dated to the early eighties; and that's 30 or so years ago now.

Ya might want to try the rifle at 200 or 300 yds and see if it settles down a bit. Mike makes an excellent point about the bullets not fully stabilizing in the first 100 yds or so (...i know that sounds crazy, but it's true....). I would try at 200 to 300 yds on a calm day and compute my moa (...ive got a 300 win mag that does this all the time. The bullet simply doesnt stabilize until after at least 100 yds or so...). Ya might be pleasantly suprised. Keep in mind that .7 inches at 100 yds is 2.1 at 300 yds. Agout the distance from the center of a hawgs nose to his eye. I say that's pretty damn good shootin.

Let us know how things turn out.

leroy

L

[gregintenn]

LOL! Shooting 1/2" groups with a factory rifle and factory ammunition? Your barrell isn't worn out; it's a gem! A lot of folks on the internet are simply full of $##+. Very few of us can shoot better than that with any rifle. Also, there are a great majority of four and even five digit custom rifles that will not outshoot yours. I feel that your expectation is more out of whack than the rifle.

[vujade]

thanks for bringing me back to reality guys!

I just loaded up on some 168 bullets from the store. Hope to reload some this weekend and hopefully back to the range in not too long of a time!

[Dolomite_supafly]

I used to load to the rifling with my Savage and it shot well enough, .5". Then one day I was shooting some different loads that were loaded to the lands. Those rounds shot miserably and turned in groups that were over1" at 100 yards.

I got so disgusted that I didn't want to shoot the ammo any more. The only other ammo I had was some rounds for my AR that were loaded to mag length. There was a huge difference between the two in length and I honestly thought they were going to shoot bad as well. In the end I shot several .3" groups using this ammo that made a big jump.

All guns are different, some like short jumps while others long jumps. Weatherby have throat lengths that are among the longest out there for a factory gun and they shoot great.

There are also certain loads that seem to do well in all guns. That is why FGMM shoots so well, it is a known sweet spot for most gun.

What you need to do is do a ladder test with the rounds loaded to factory length. Then you need to do the same ladder test using different lengths.

It is also important to seat the bullet off the base of the ogive. you might need to open the seater pin slightly to do this. I made a seater that is only .002" smaller than the bullet.

Dolomite

[vujade]

3 hours later and I loaded about 25 ish rounds. =)

thanks for the info Dolomite. I started with a ladder test a few weeks ago (my first session) (42 grains all the way to 44something in .5 increments. the 42 seemed to be best). the 25 something rounds I just loaded were loaded with 42 grains since that seems to be the best) starting with a 2.800 OAL (replicating the factory Hornady TAP which the guns likes and I'm using similar bullets (the 168 AMAX with the red tip). I made some at 2.830. then 2.860 and finally just a few rounds to retest the ones I was disappointed with last time (2.890) (which is .030 to the lands).

I hope to test it tomorrow!

[vujade]

another OAL related question...

When I reseated some of the bullets, they seemed loose. I was able to compress it down into the case with the calipers while measuring OAL. I know that's bad since it will increase pressure.

I pulled it out somewhat and now it holds and it's still within the OAL i'd like. I assume with a semi-auto, that's probably bad. but since I'm using a bolt action and single feeding slowly, it should be ok right?

I decided to not crimp yet (one less thing to buy for now) since I'm not running them on a semi auto anyway.

the bullets that seem to do this (just a handful) I believe were previously pulled out (since I see marks like they were once loaded. I pulled the bullet out and redid a few with AMAX from the box and it seemed to hold. hmm. (i measured them and they are all the same diameter).

[vujade]

First, i know these are only 2 groups but after much experimenting..i think i found the right load and OAL combination. Thanks everyone who's helped! It's been a huge learning (and continues to be) opportunity.

I shot the group on the bottom first. I couldn't see if I hit anything since i replaced the Nikon 4-14x got and a fixed 10x scope instead.

I then shot the group on the top.

There was a range clear and I walked to the target in surprise!

100 yards. Savage 10FP. I changed to a SWFA SS 10x scope. 168 Hornady TAP. 42.1 grains of Varget. win primers. Fed cases. OAL 2.857 (.60 to the lands).

I just made some more. I'm sure the stars aligned for the groups above and there was some luck there. (I think my rifle is just a .60 to .75 rifle; at least most of the groups are about that) but it's nice to get a nice group you can cover a dime with.

When I got back to my bench, a guy to my right set up to shoot a muzzle loader and the guy to my left had this round that looked a good 50% bigger than my 308! Nice rifle but Geez it was loud and was literally pushing me with his muzzle blast. So i stopped there and called it a day. =)

Edited July 14, 2012 by vujade