Have a couple questions to start: Im loading for a Yugo M48 Mauser, and have chosen to try the 180gr Nosler Ballistic Tips over IMR4064.

I've 'gauged' the chamber using the black marker/bullet/empty case method and come up with 2.901"

I've gathered from some of the other reloading forums that I should start with 44gr up to a max of 49grs. (If someone here feels different PLEASE advise )

Now, I've begun to load up the rounds using the recommended 44gr of IMR4064. Heres what I've noticed (and please excuse the beginners wording) - Firstly, I've of course trimmed the cases to their 'trim to length of 2.235'

Upon charging the case its observed that the casing is about 85% full and comes up to shoulder of the case. When I seat the bullet, I've been trying to get it to the 2.901" at least - but my concern is, am I seating this bullet too deep for this powder/load? I know the possible sweet spot is .010" to .040" off the lands but I think I'll have to settle for at most, 2.900" to guarrentee these rounds would be above the acceptable minimum.

However at this point, with seating the bullets at 2.900-2.903, the base of the boat tail bullet is 'in' the powder. Need I worry about pressure issues, or seating the bullet to 2.900 or beyond (but no more than 2.850")?

It just seems (to this newbie) that these 1.275" bullets are too long to be seated that deep. The bullet is no doubt secure in the neck of the case - but is there such a thing as "too deep" (aside from published min AOL)??? I would much rather pull the bullets and reseat to 3.00" than risk pressure issues.

All other case measurements have been taken and are within the maximum variences.

Thanks in advance for your replies!

It's called a compressed charge. It is normal for small cases such as the .308 Win. and 8x57 family of cases. As long as you're sticking to proven data and aren't touching the lands with the bullet, you should be fine. When you get over about 90% load density, you will be pushing the bullet on top of the powder. Put a caliper on finished rounds to check the OAL to be safe.

I picked up some 180 gr. NBT for my Yugo the other day also, can't wait to load them.

CAL

A word of caution: don't let a slight variation in COL alarm you. Some of the Balistic Tip bullets I have measured vary a few thousandths in length, due to variance in the polymer tip. This will not alter the relationship of the ogive to your rifling.

Your COL of 2.901" seems rather short. The SAAMI COL for the 8X57 is 3.250" I think. Lengthening your throat some would give you more flexibility, and perhaps a small increase in performance by allowing more powder to be burned without increasing pressure.

Is 2.901" the COL (Cartridge Overall Length) or the distance to the rifling? If it is the later, then disregard my comment on lengthening the throat.

Oops, I just realized you are shooting a 48 Yugo! This is an "intermediate length" large ring M98 and will not accept a COL of 3.250" Please disregard my suggestion to open up the throat as you are near max COL as it is. You should still be able to get about 3.150" to 3.200" COL if your throat were long enough though.
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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

[This message has been edited by wildcat junkie (edited 02-20-2002).]

Wildcat - The 2.901" is actually the Cartridge Overall Length from the marker/bullet/empty case chambering. So Im clear, the measurement refers to the actual dummy case length that I've created by seating the bullet to the farthest 'scuffed' off marker area where the bullet met the lands. I'm always wary of the minimum overall length, so I'm trying not to seat it much below 2.885 (but I think the variations that I'm getting between 2.885 to 2.901 are in fact from the 'ballistic tip' variance.

I'll give her a go round this coming Monday and post the results. I do agree however, I might want to consider a faster burning powder, a flatbased bullet and/or an entirely different powder bullet combination if I have no other option than to seat the rounds that deep.

With factory Federal Classic 170gr loads that I used in this rifle, I think they were at least 3.00" COAL (Unfortunately I never measured them)- and I was getting 3.5" groups at 100yds. Not the greatest, but if my seating depth should be 2.900, it might explain the less than great accuracy.

[This message has been edited by HKgnnr (edited 02-21-2002).]

quote:

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Originally posted by HKgnnr:

I'll give her a go round this coming Monday and post the results. I do agree however, I might want to consider a faster burning powder, a flatbased bullet and/or an entirely different powder bullet combination if I have no other option than to seat the rounds that deep.

[This message has been edited by HKgnnr (edited 02-21-2002).]

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HK: A faster burning powder may give you some better performance, but I doubt if it would be signifigant. From what I understand from what I have read and heard, IMR 4064 is known as "the Camp Perry powder" from it's reputation of consistant performance in the 1000yd "Hi-Power" matches. The case capacity of the 8X57 is similar to(perhaps slightly more)the 7.62 NATO (308 Win) I am not speaking from experience, just what I have gathered from reading and listening.

What I do know from experience is that The 8mm Nosler 180gr Ballistic Tip/IMR 4064 combo is the most consistent performer in my 8mm-06 A.I. The 180gr BT shoots flatter (from observed impact points @ various ranges)than the 175gr Sierra with the same powder charge. I use the 175gr Sierra for fire-forming and plinking due to it's lower cost.

I have experimented with Varget, IMR 4320 and IMR 4064 behind the 180gr BT. The 4320 and 4064 give similar accuracy with the 4064 giving the smallest Standard Deviation. IMR 4320 seems to give more muzzle blast and perceived recoil, but that is just my impression, and is not backed by any scientific data. All give similar velocities with similar charges of powder. Slower burning powders (IMR 4350 and RL19) resulted in about 200fps less MV with no better accuracy. All of this data was gathered with a Pact chronograph, and is not based on conjecture, but actual velocities measured by instument.

In a nutshell, in my opinion you are probably near the best bullet powder combo. By all means experiment, but I doubt if you will find a combo that gives a signifigant increase in performance, either MV or accuracy. I harvested 3 Whitetails with the 180gr BT last year @ ranges varying from 60yds to 225yds, broadside and quartering away respectively. The exit wounds were similar,(about "tennis ball" size) indicating that this bullet performs consistently over a wide range of velocities. For game larger than Deer, a heavier bullet (200gr Nosler Partition?) might be in order.

You might want to investigate having the throat lengthened to allow a longer COL. The cost would be minimul. Your mag well should measure about 3.235", allowing a COL of about 3.150, allowing a little room to grow as the throat erodes after many 1000s of rounds. That will allow a .250" increase in COL allowing a pretty good increase in performance, and a little more flexibility with heavier bullets. If you supply a "dummy round" of that COL, a gunsmith can "throat your chamber accordingly.

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

[This message has been edited by wildcat junkie (edited 02-22-2002).]

[This message has been edited by wildcat junkie (edited 02-22-2002).]