Model 10 Predator Hunter. Short Chamber/Freebore?

[John Model 10]

Yesterday, I picked up my new Model 10 Predator Hunter in .243 Win. I had already done up a few handloads for it and tested them for function/cycling (but did not fire it yet), last night. A couple of them required a little extra force to close the bolt, which surprised me, as this is virgin Winchester brass which measures within spec. I also noticed that, of the three different bullets used, all of them exhibit some signs of touching the lands, but one was more pronounced than the other two. Here's the details:

Sierra 80g SP
Started at spec length of 2.710". However, after chambering three of them, I found that they all gave a little resistance to closing the bolt. One of the three being notably harder to close. When I ejected them, I noticed that they all had distinct marks from the lands and they all were pushed back to approximately 2.665" in length. I was surprised at this, being quite a change and well under spec length.

Hornady 87g V-Max
Started with a length of 2.712". These seemed to chamber easier, but still show slight signs of touching the lands. No change in length after being chambered, however.

Hornady 100g SP Interlock
Started at a length of 2.710". Like the V-Max above, no change in length and not hard to chamber, but showing slight signs of touching the lands.

Without doing a closer comparison, I'm going to assume that the ogive of the Sierra 80g SP is set longer than those of the two Hornady bullets. But still, this seems a little short and was alarming, as my 10FP in .308 is the opposite, having a very long freebore. So, I guess I have two main questions. First; is this something I should be concerned with? So far, it seems only to be a real issue with one bullet and I could probably work around that, anyway. Second; has anybody else experienced this? I saw another thread with similar issues in a new 10FP, but it has not been determined yet if it was a brass issue or a short chamber issue.

This is my first .243, so I want to avoid any critical errors in handloading for it. I think that, as it sits now, I can work with it, but was just surprised to see such a tight tolerance. It would not bother me if I didn't have to extend my OALs, as I do with other calibers, so long as it shoots like it should and safely. What do some of you gurus think?

Thanks in advance,

John

[tammons]

I would be concerned.

If its a jumped hand load and now its jammed way into the rifling on a zero freebore rifle you could have a pressure problem
and probably exacerbated because its an overbore 243. According to this post and the previous 10FP post it sounds like savage is changing things again.

If you think about the microsecond chain of events....
The primer pops and lodges the bullet in the rifling. If you have a long freebore
then that allows more room for powder expansion and keeps the pressure spike down.

If zero freebore the bullet will move very little, so higher pressure.

Dont know why they are changing things.
They changed the 7mm-08 twist rate and now it sounds like they are going to short throats which makes no sense to me.
Maybe its just a coincidence and you both have bad barrels.

To really know what you guys have you need to slug the barrel.
I would call savage and check if this is normal or just send the rifle in.

I run my 308 208 amax loads at 2.93 and if that did not work in a new 308 rifle I just bought I would be Pi$$ed.

[John Model 10]

I would call savage and check if this is normal
Tammons,

I took this advice (and sound advice it is) and gave them a call. I had to relay the info through the lady on the phone and back from their "head gunsmith" and was told that they are tested with factory ammunition. We discussed the fact that factory ammo is typically not loaded to full spec length. I was told that, if I sent the rifle in and they found nothing to be wrong with it, I would be charged for any labor. The fact that I was using handloads didn't seem to sit well with them (which I expected), but we came to the conclusion that the rifle is "in spec" by their definition. So, I would not be surprised if this isn't the only rifle out there that is being built to this specification (and judging by the claims of some others, it is not). I think they have us in a precarious postition, however, since factory loads should be no trouble, but if you want to handload, you're going to have to deal with the tighter specs and there's not much you can do about it, for reasons of warranty.

Now, on the positive side, I don't think this is going to be an issue for me, personally. I have no plans to use VLD bullets, or the need to seat any bullets out, so long as it shoots as it should and is not showing any signs of excess pressure, which it is not. I shot the rifle this morning and was more than pleased with it. I think, since I'm careful about my loads (which is how I found this to begin with), I can work around this without too much trouble. But, if it ruffles some people's feathers, I can completely understand. But, given the groups I got this morning (I'll post a range report on the Centerfire forum), I don't really want to change a thing!

Thanks for your input,

John

[GabbyM]

I think you may be simply loading long. Just checked my Hornady book and in 243 Win the 100 grain SP is listed at 2.630” COL. Checking my personal load book I have loaded Sierra 80 gr SBT at 2.710” which curiously is the same as you listed. That was measured out to the lands plus .005” at the time. But this was a barrel with a few hundred rounds down the tube. 243 Win will wear the throat forwards is short order. The Sierra load book shows a COL of 2.635” for the 80 gr SBT Blitz. This data can be found on the Sierra web site. You're .075” over that so it's no surprise you're tight.

[John Model 10]

Gabby,

I've loaded a couple batches with the 80g SP to 2.650" and had better success with them. So, you're absolutely right. The data in my Lee manual is similar and points in the same direction. For now, I'm going to wait with any further testing, until I get my new scope (should be a couple weeks). I did get the chance to shoot one group at 306 yards. It was the 87g V-max and I put four into two inches, with the fifth being a called flyer that was just over an inch lower. I still think the gun is more capable than I am, or the optic that I was using. We'll see what it does with some good glass.

Thanks!

John