H4895 Data

aocasek · Post by **aocasek** » Mon Jul 30, 2007 1:54 pm

Not sure if this has been covered before but when using the 39 BK is it OK to sub data for the 40 gr. hornady? My sierra manual says max for the 39 BK is 26.6 of H4895. Hodgdon says the max for the 40 hornady is 27.7 C of H4895. Why the big difference?

I know lots of you guys load more than 26.6 with the 39 BK. I'm planning to work up very carefully because on my vertical stringing post the consensus was I needed more powder, my load is 26.1 of H4895.

Also, will seating the bullet further out, (mine is 2.250) give more velocity? I was planning on moving it out by .010 per time, is that the right way to go about it? I know won't be able to get close to the lands because of the magazine of my 527 and the long throat but I'd like to play with the depth to see what happens.

P.S. In regards to my vert. stinging post...I backed off of my load and switched primers to the CCI450 (was using the BR4) and worked back up and it cut an inch off my group size at 300 yds. Now that load is shooting around 1.0 to 1.25 at 300 yds. BR4 groups averaged 2.5. Is that what I should be looking for? Thanks guys for the advice, this site has been a big help.

Adam

kirbymagnum · Post by **kirbymagnum** » Mon Jul 30, 2007 3:09 pm

Not sure if this has been covered before but when using the 39 BK is it OK to sub data for the 40 gr. hornady? My sierra manual says max for the 39 BK is 26.6 of H4895. Hodgdon says the max for the 40 hornady is 27.7 C of H4895. Why the big difference?

From my experience it is safe to use Hodgdon load data for the 40 V-Maxx with the 39 BK. The temperature was 95 F and I used Federal 205 and Remington 7-1/2 primes with max loads and no signs of excessive pressure.

I would also like to know about playing with seating depth.

WrzWaldo · Post by **WrzWaldo** » Mon Jul 30, 2007 3:27 pm

aocasek,

Have you looked here for the 39BK load data? --> http://www.rugerhunting.com/204_data_sierra.php

skipper · Post by **skipper** » Mon Jul 30, 2007 5:01 pm

aocasek
kirbymagnum

After you find a bullet, powder, primer and case combination that your rifle likes then start adjusting your seating depth. I would increase OAL (base to tip) in .005 increments. Load five shots at each length and shoot for groups. You will have to determine if you have magazine length restrictions. That may limit your OAL. If you don't have magazine length restrictions you can go all the way out to about .010 off the lands.

You will need to exercise some good judgement. Normally the recommendation is to leave at least one bullet diameters length in the case for proper neck tension. There are others that think you only need to leave half the bullet diameter in the neck. If your bullets are seated so far out that they fall out of the case when bumped, that isn't good.

I did an experiment with my XR-100 about a year ago. I loaded rounds from 2.250 out to touching the lands (with a reduced charge) and headed to the range. In the end I found that my rifle liked 2.255 better than any other length. Go figure!

If you are going to adjust your seating depth, please do so carefully. Get a Stoney Point OAL gauge to measure the length to the lands precisely. You can get in trouble with pressures if you load a round too long so that it is touching the lands with a hot load. The bullet can't start moving and relieving the pressure like it can when it has room to jump. Pressure spikes are extremely dangerous. The .204 case size builds pressure rapidly anyhow. Just keep .010 off the lands and you should be fine. Take measurements with a comparator that measures off the ogive. Don't use base to tip measurements. (OAL) Your seating die doesn't push on the tip of the bullet anyhow. It's hollow on the end of the stem and pushes at the ogive itself. That's why you get varying readings while seating and measuring with a set of calipers. Bullets can have different measurements from the ogive to tip. Measure from the ogive, that's where the bullet will contact the rifling anyhow. The tip doesn't touch anything going down the tube. Good Luck.

aocasek · Post by **aocasek** » Mon Jul 30, 2007 7:31 pm

WrzWaldo wrote:aocasek,

Have you looked here for the 39BK load data? --> http://www.rugerhunting.com/204_data_sierra.php

Yep, the max charge for H4895 and the 39 BK is 26.6 according to sierra, if you click on Hodgdon, it gives a max load of 27.7 C for the 40 V-Max...

acloco · Post by **acloco** » Tue Jul 31, 2007 6:00 pm

kirbymagnum wrote:
Not sure if this has been covered before but when using the 39 BK is it OK to sub data for the 40 gr. hornady? My sierra manual says max for the 39 BK is 26.6 of H4895. Hodgdon says the max for the 40 hornady is 27.7 C of H4895. Why the big difference?
From my experience it is safe to use Hodgdon load data for the 40 V-Maxx with the 39 BK. The temperature was 95 F and I used Federal 205 and Remington 7-1/2 primes with max loads and no signs of excessive pressure.

I would also like to know about playing with seating depth.

..and my Savage 12FV is at max load at 27.7....I stay in the 27.4 range up to 85 degrees and 27.0 above that temp.

I don't care how fast the bullet is travelling, only if it is accurate.

.204 Sniper · Post by **.204 Sniper** » Fri Aug 03, 2007 12:03 am

I agree with Skipper.................I would also like to add using a gauge from Sinclair Intl. that measures OAL from the OGIVE of the bullet - NOT the tip. That way if you change brands of bullets that have a slightly different nose profile, you can load to the exact OAL (ogive) as another given bullet.

This worked tremendously for me in my .308 and my .250 Ackley.

BunGhoLeo · Post by **BunGhoLeo** » Fri Aug 03, 2007 11:03 am

I've been thinking about this allot as i'm buying stuff for reloading.

It seems to me the only accruate way to measure base to ogive for a piticular rifle, would be to seat a bullet in an empty case, and chamber it to see if it hits the lands. Repeat until it starts hitting. Then you can set your Redding compitition seating die at zero, and you can adjust the seating depth per the micrometer on the die.

And if your loading for two or more rifles of the same caliber you just go thru the procedure of when you start touching the lands, then put on your load sheet the offset needed for that piticular rifle. I imagine this would need to be done for differant bullets as well.

All rifles are differant, chamber depth, headspace, freebore, rifleing diameter, and bullet make&model will all effect it.

.204 Sniper · Post by **.204 Sniper** » Wed Aug 08, 2007 11:20 pm

Here 'ya go.................
http://www.sinclairintl.com/cgi-bin/cat ... type=store

Find your OAL to the lands with a tool that measures to the back of a bullet you place in the chamber (not loaded into brass). You then place a piece of empty brass in the chamber (after removing the bullet) and measure to the back of the case.
There are metal cylinders on a metal rod you slide up and down during this process. When your finished, you measure the distance between the two cylinders with your calipers and you now know the exact depth to the lands of your rifle.

I forgot the name of the tool or who makes it - I'm sure other members will chime in here and help.

Once you know that measurement you use your Comparator to get a precise seating depth with ANY bullet ogive configuration. Just remember your comparator adds exactly 1" to your OAL measurement.

If you want a seated bullet depth of 2.255" - it will mic out at 3.255" using a comparator.

This is by far the BEST way to play with seating depth because it is repeatable consistency.