Author Topic: Simple OAL Gauge. (Read 6968 times)

Fred M · « **on:** February 23, 2007, 05:01:08 PM »

With a Dremel cutting wheel spit the neck on fired and sized case. Pinch the neck a bit insert a bullet and feed it into the chamber. The bullet will slide into the neck when it touches the lands. Measure the lenght and deduct or add whatever suits your fancy.

I use this type of gauge in all my rifles and calibers.

Edit
Forgot to mention when using this gauge in a bolt action with the ejector button in the bolt face you have to hold yor finger against the case when you pull out or it will flip or bear aginst the side of the action and give you a false reading. With a bit of practice you get the hang of it

You should also take three readings rotating the case a bit.

MSP Ret · « **Reply #1 on:** February 23, 2007, 05:08:11 PM »

Thanks Fred, simple tools like this are what I like best....<><....

ONE HOLE 4570 · « **Reply #2 on:** February 23, 2007, 05:10:48 PM »

now there's an idea, need to keep busy on those long cold Canadian prarrie nights(dads from Dauphin Manatoba now in Victorial uncle in ft Mcmurry BUUURRR

)

quickdtoo · « **Reply #3 on:** February 23, 2007, 05:23:09 PM »

Great idea Fred, a good addition for the FAQs!

Thx,

Tim

Fred M · « **Reply #4 on:** February 23, 2007, 05:37:40 PM »

Tim I added a note for bolt actions.

quickdtoo · « **Reply #5 on:** February 23, 2007, 05:58:00 PM »

What's a b...b....bo....bolt action!!!

McLernon · « **Reply #6 on:** February 23, 2007, 06:06:55 PM »

Good stuff, Fred!!

Mc

McLernon · « **Reply #7 on:** February 23, 2007, 06:10:22 PM »

Tim, you mean a b---b------bo------bo-----------bol------------bol------bol----t --- bolt action??? Never heard of 'em.

Mc

quickdtoo · « **Reply #8 on:** February 23, 2007, 06:14:08 PM »

dave hall · « **Reply #9 on:** February 23, 2007, 10:02:56 PM »

I had one of those B guns once

in a Ruger 350 Rem.Mag..I found them to be to bulky.I love single shots.My newly made 45-90 Handi and a couple of the now way over priced

#1's seem to me anyway to be a lot more fun.Dave

cbourbeau32 · « **Reply #10 on:** February 24, 2007, 01:32:32 AM »

Thats a really neat tool. Now a technical question related to it. Do I want to end up as close to the lands as possible with my OAL or is there a particular distance away from the lands that I need to end up with for best accuracy? Thanks, Charlie

bigjeepman · « **Reply #11 on:** February 24, 2007, 03:17:57 AM »

Excellent work Fred ... simple, effective, and economical ... gee ... that sounds like a Handi !!!! I am making one for each of my calibers today ... I have been using Stoney Points OAL Gauge but will give Fred's idea top priority this weekend ... well, since I am now married maybe not top priority.

Fred M · « **Reply #12 on:** February 24, 2007, 09:12:16 AM »

OK guys I got that Idea from the Stony point a long time ago, made a copy of a Stony point and found it lacking. Too touchy when using the screw on the stony point, I found the the case backing out given a wrong reading.

With my gauge you have no screw. The bullet stops at the lands. You just have to make sure the bullet has enough friction so it willnot pull out when you extract the case. Some throats with certain bullet ogives will grab the bullet.
Always take several readings and compare with the previous one. They usually are within 2-3 thou of each other.

The bullet you use for the OAL, is the one you should use to set your seating die this will assure the OAL is taken from the ogive. Bullet tips are not all the same.

Setting your bullets 0.020" off the lands is a good standard. Barnes recommends their bullets to be seated 0.050" off the lands.

Just remember when seating a bullet against the lands or into the lands your pressure goes up by at least 7200psi with Barnes bullets it goes up to 11500psi.

When playing around with seating depth you better use a chrono and interpret unusual velocity increases. Meaning too much pressure with the same amount of powder.

handirifle · « **Reply #13 on:** February 24, 2007, 11:11:33 AM »

Fred, I hate to tell ya but it looks like your firing pin went just a little too deep

, Why'd you put threads on it?

Fred M · « **Reply #14 on:** February 24, 2007, 12:07:33 PM »

Handirifle.
It is not the question that is hard, it's the answer.

Mac11700 · « **Reply #15 on:** February 24, 2007, 12:29:21 PM »

Quote from: Fred M on February 24, 2007, 09:12:16 AM

OK guys I got that Idea from the Stony point a long time ago, made a copy of a Stony point and found it lacking. Too touchy when using the screw on the stony point, I found the the case backing out given a wrong reading.

With my gauge you have no screw. The bullet stops at the lands. You just have to make sure the bullet has enough friction so it willnot pull out when you extract the case. Some throats with certain bullet ogives will grab the bullet.
Always take several readings and compare with the previous one. They usually are within 2-3 thou of each other.

The bullet you use for the OAL, is the one you should use to set your seating die this will assure the OAL is taken from the ogive. Bullet tips are not all the same.

Setting your bullets 0.020" off the lands is a good standard. Barnes recommends their bullets to be seated 0.050" off the lands.

Just remember when seating a bullet against the lands or into the lands your pressure goes up by at least 7200psi with Barnes bullets it goes up to 11500psi.

When playing around with seating depth you better use a chrono and interpret unusual velocity increases. Meaning too much pressure with the same amount of powder.

Hey Fred...I think you mean the regular Barnes bullets...not the Triple shocks...This is from the new Barnes web site..http://www.barnesbullets.com/information/bullet-talk/x-citing-facts/

Multiple grooves machined into the shank of each Triple-Shock X-Bullet reduce the bullet’s surface area that contacts the bore, while bourrelet length remains unchanged. The result? Triple-Shock X-Bullets create less fouling and pressure buildup than almost all competing bullets. Their unique, one-piece design and generous bourrelet produce unsurpassed stability and exceptional accuracy. With no lead core to fragment or shear away, Triple-Shock X-Bullets retain virtually 100 percent of their original weight for deep, sure penetration.

Mac

Fred M · « **Reply #16 on:** February 24, 2007, 01:51:08 PM »

Mac.
I use the TSX bullets a lot, and are quite familiar with their behavior. I think I was one of the first to use them on this forum in a Ruger #1 25-06.

Above I am talking about on or into the lands. The reduced grooved surface aria on the BarnesTSX shank does nothing when bullet is engaged into the lands. The pressure goes up since there are no grooves in the ogive and no initial free travel.

That is why Barnes recommends 0.050" off the lands. I think that applies to all their solid copper bullets. Anybody using these bullets should stick with the Barnes recommendation.

All solid metal bullets, mainly solid brass and copper, produce higher initial chamber pressure, once they pass the throat the grooves come into effect and reduce the pressure, or speed up the bullet because of less friction.

For your info. The initial chamber pressure for most regular Jacketed bullets is approx 3625psi, Solid copper is 6325psi, add 7200 to both when on or into the lands. Friction proofing will reduce these figures, my 11500psi above was based on moly plating.

The subject was a simple OAL gauge now look what we got into, because someone wanted to know where to go when the bullet hits the lands. I guess a simple explanation is not good enough.

carbineman · « **Reply #17 on:** February 24, 2007, 02:34:16 PM »

Fred, Thanks for the idea. I am going to start with the TSX's in my buddy's Savage bolts in .308 and 7mmSTW. We'll be sure to make up an " Fred's OAL guage"

OR-E-Gun Bill · « **Reply #18 on:** February 25, 2007, 11:31:52 AM »

Fred, in developing loads using the .0" to .020" off the lands method, do you have a minimum depth (bullet inside the case contact) that you try to achieve?
A point where you say, "there just isn't enough bullet contacting the inside of the mouth to be safe"?

Thanx,

Bill

Fred M · « **Reply #19 on:** February 25, 2007, 12:35:10 PM »

Bill
Quote.
in developing loads using the .0" to .020" off the lands method, do you have a minimum depth (bullet inside the case contact) that you try to achieve?
A point where you say, "there just isn't enough bullet contacting the inside of the mouth to be safe"?

This is hard to answer, I have loaded bullets in lighter varmint calibers only 1/8" into the neck. In general one bullet diameter is best.

The idea of getting close to the lands is a matter of concentricity, meaning the bullet tip is in the center of the bore and will not bounce off one side or the other.

When neck sizing only do the top 2/3 of the neck only. The other third is left unsized and enters the neck as fired. This will center the case. That is also why I do a partial outside neck turning.

Of course if you have to set the shoulder back and only have a standard die this type of neck sizing is not possible. Custom dies is another story, they are nice but expensive.

If a bullet is not seated and loose in the neck you get blow by that can travel back to your face.

Of course if you have a cockeyed chamber, and long free bore some of these ideas are accademic. With the Handi long free bores it is best to have at least 1/4" of bullet in the neck.

quickdtoo · « **Reply #20 on:** February 25, 2007, 06:30:56 PM »

Thanks Fred, your contributions are sincerely appreciated!!

Tim

OR-E-Gun Bill · « **Reply #21 on:** February 26, 2007, 09:59:39 AM »

Fred's Quote: "Of course if you have a cockeyed chamber, and long free bore some of these ideas are accademic. With the Handi long free bores it is best to have at least 1/4" of bullet in the neck."

Thanks Fred.
The long free bore is the problem I'm finding in my Handi .223 / 1:9 twist. Of the bullets that I've tried fitting (mostly V-Max) the 55 gr. is the smallest I've been able to reach the lands and that is with .125" inside the case mouth.

Bill

dave hall · « **Reply #22 on:** February 26, 2007, 03:54:05 PM »

Do you check a straight wall case like the 45-70 or 45-90 the same way.I'm going to try the X bullet and the TSX out of my 90.I'm going to get the cutting bit an try it.I'm going to check all my different bullet types to see where they sit so I will know.Dave

Fred M · « **Reply #23 on:** February 26, 2007, 04:21:49 PM »

Dave I don't see any reason why this gauge wont work on straight cases. Just make sure there are no burrs on the in and outside of the cut.

I think with these heavy copper bullet it is even more important to know how far they are away from the lands. They do need that extra free travel for sure.

With the gauge you can find the best free travel to suit your throat, a worn throat will be less of an impediment and allows for a bit closer to the lands. A bit of testing will tell you.

dave hall · « **Reply #24 on:** February 26, 2007, 05:06:58 PM »

Thanks Fred,I just redid my 70 into a 90 and I've only put 30 45-70 and 7 45-90 rounds down the barrel since I got it so the throat not worn yet.I'm going to try the 250 TSX up to the 450TSX .I got some Barnes 500 banded solids coming from hunman55 to play with.So I'll give your system a try Tomm.I'll let you know how it turns out.Dave

The Great .458

quickdtoo · « **Reply #25 on:** February 26, 2007, 05:21:29 PM »

Dave, check with Barnes, the 450 TSX may not perform reliably at any velocity the .45-90 can produce, that topic was discussed on another forum.

Tim

Fred M · « **Reply #26 on:** February 26, 2007, 06:20:03 PM »

Tim.
Your are right. These copper babies are longer and the do love the speed, the faster the better. I am sure there is nothing walking away from these 250gr TSX bullets.

dave hall · « **Reply #27 on:** February 26, 2007, 07:45:46 PM »

How about with the TSX I'll stick with the 250 and the 300 that are made for the 45-70.I won't mess with the 450's.Now can I use the Barnes solids at lower velocitys.I got 33 of them on the way.What section of load data in the Barnes manal #3 should I use for the 90.Marlin or #1.Thanks for the info guys.Dave

quickdtoo · « **Reply #28 on:** February 26, 2007, 08:17:01 PM »

Marlin or #1 data for the .45-90???

I don't think there is any, is there?

dave hall · « **Reply #29 on:** February 26, 2007, 08:27:48 PM »

The data for the 45-70 is what I'm talking about .I'm looking for a good starting point.dave