OAL Questions

[English Mike]

I'm starting to reload some .270Win. for a specific rifle.

Cases have been trimmed to 2.53" as per the book.

Bullets are Hornady SST 130gr.

The maximum OAL in the manuals is 3.34".

The Speer & Lyman manuals give an OAL of 3.24" & 3.25" respectively, for a 130gr bullet.

I used a Stoney Point OAL gauge to check bullet seating depth & with the bullet touching the lands, I get 3.38". This is 0.04" over the Max. OAL & .14" over what the books suggest.

Obviously I'm not going to seat them at this but from what I've read seating bullets reasonably close to the lands improves accuracy, so I'm minded to set the OAL at 3.33" initially for working up a load - some 0.05" back & work up from there to 3.36".

Does this sound OK, so long as the rounds fit the magazine?

[jerrymrc]

Originally posted by ENGLISH MIKE
I'm starting to reload some .270Win. for a specific rifle.

Cases have been trimmed to 2.53" as per the book.

Bullets are Hornady SST 130gr.

The maximum OAL in the manuals is 3.34".

The Speer & Lyman manuals give an OAL of 3.24" & 3.25" respectively, for a 130gr bullet.

I used a Stoney Point OAL gauge to check bullet seating depth & with the bullet touching the lands, I get 3.38". This is 0.04" over the Max. OAL & .14" over what the books suggest.

Obviously I'm not going to seat them at this but from what I've read seating bullets reasonably close to the lands improves accuracy, so I'm minded to set the OAL at 3.33" initially for working up a load - some 0.05" back & work up from there to 3.36".

Does this sound OK, so long as the rounds fit the magazine?

Yes.:bigangel: :beer: :beer: :beer:

[shootist87122]

Be sure that at a minimum, you seat the bullet the equivalent of one bullet diameter into the neck. Also try a few at the shorter COL suggested in your manuals. Sometimes a little jump works best (you won't know till you try).

[English Mike]

Originally posted by shootist87122
Be sure that at a minimum, you seat the bullet the equivalent of one bullet diameter into the neck. Also try a few at the shorter COL suggested in your manuals. Sometimes a little jump works best (you won't know till you try).

There's still way more than one caliber inside the neck Joe, though the cannelure is a good 0.01" above the neck.

Put some Prvi-Partizan JSP through the rifle a couple of weeks ago: 3.2" OAL & it wouldn't hold to 3" @ 100yds.

I'm not the one paying for the components, so there's plenty of scope for testing.:D

[W.E.G.]

You didn't say what brand of rifle this is.

Some commercial rifles have ridiculous-long throats and very mediocre-quality barrels.
3 MOA may be all that barrel is capable of.

[shootist87122]

Mike,

Privi is not exactly the "good stuff". I bet you can cut that 3" in half or better. Keep us posted.

Joe

[English Mike]

BSA - mid 70's from what I can find out.

Possibly the throat is eroded, though visually it looks fine.

[W.E.G.]

That would take some hard-core shooting to significantly erode an otherwise-good throat in in a .270 bolt-gun.

You might want to use a Stoney-Point throat gauge to find out how much jump you are dealing with. Some guns like a very small amount of jump. Although, most seem to shoot best when the bullet is just "kissing" the rifling.

Remington is known to cut throats unreasonably long to keep yahoos from jamming too-long rounds hard into the rifling. Damn shame that somebody would spend $1000 on a rifle, and then not spend the extra money for the right tool to measure the throat to be sure they don't use incompatible ammo.

[English Mike]

Originally posted by W.E.G.
That would take some hard-core shooting to significantly erode an otherwise-good throat in in a .270 bolt-gun.

Aye - I think it was probably cut fairly long & with the brass trimmed to minimum it just looks longer. Even at 100 rounds a year, the erosion wouldn't be more than 0.015" & for what is a deer rifle that would be a lot of shooting for here.

You might want to use a Stoney-Point throat gauge to find out how much jump you are dealing with. Some guns like a very small amount of jump. Although, most seem to shoot best when the bullet is just "kissing" the rifling.

That's what I mean by using the Stoney Point OAL gauge - the one that uses a modified case so that you push the chosen bullet up to the lands & measure the length. I've plenty of variables to play with & will proceed with due caution.

Remington is known to cut throats unreasonably long to keep yahoos from jamming too-long rounds hard into the rifling. Damn shame that somebody would spend $1000 on a rifle, and then not spend the extra money for the right tool to measure the throat to be sure they don't use incompatible ammo.

All being well, we should get to try out the first loads on Sunday & put them over the chronograph at the same time.

H4831 does NOT meter well through a Uniflow - jamming on powder kernels, so I'm weighing all the charges. Eejit didn't specify H4831SC when he ordered it.:rolleyes:

[gunseller]

Mike
If the roumd fits the mag you should have no problems. If you move the bullet out to create a longer OAL you might be able to add a little more powder and get more FPS out of the rifle. If you do be careful and go slow. If you do not add powder you might see a little slower bullet. The bullets you use will make more differance than the rifle. Some bullets like to be tight to the lands while others like to jump, some as much as .02.
Steve

[moses]

Well H4831sc doesn't meter well in mine either it is a clunky powder even in sc form :(

[owlcreekok]

Went and dragged out my log book after I read this earlier. Here's what my Belgian FN .270 likes. The 170 gr load doesn't work as well. Twist may be too fast. Haven't measured that. (I am embarrassed to admit)

45 grs 4895, WLR primer, 130gr Rem SP, 3.249" OAL - < 1.5 MOA

45 grs 4895, WLR primer, 150gr Rem SP, 3.249" OAL <= 1.5 MOA

47 grs 4350, WLR primer, 170gr Speer RN, 3.134" OAL barely 2 MOA

Seems about .010" freebore works best in this one, IIRC, with 130 thru 150 gr bullets. I haven't tested the heavies as much in this regard. Only using them because I got them and to see what I can get out of them. I'll use them in the field if results stay as good or get better.