Gunsmithing Anyone know the throat dimension for a 284 win?

[pyplynr]

I got home from work today and my brand new Shilen Savage pre-fit barrel chambered in 284 win by Shilen themselves was here. I put my Hornady OAL gauge in the chamber to check it out. Here are the horrible results:

162 Hornady Amax
Base to Ogive - 2.521"
OAL - 3.325"
175 SMK
Base to Ogive - 2.683"
OAL - 3.332"
180 Berger Hybrid
Base to Ogive - 2.668"
OAL - 3.408

Should I call Shilen or call the company/middleman that I bought it from?

 

[geargrinder]

Re: Anyone know the throat dimension for a 284 win?

I'm confused by your base to ogive measurements changing so much. They are usually very close to each other.

The ogive is supposed to be about where the lands engage the bullet. The distance from there to the base is a constant.

 

[doc76251]

Re: Anyone know the throat dimension for a 284 win?

Concur with gg, something wrong there.

I've never liked the Hornady OAL gauge as the results are never consistent IMHO. Do the sharpy thing.

Of course check all the other variables first, make sure the nut is tight, chamber and raceways clean, bolt lugs clean, cdtg seated past the extractor etc...

Cheers,

Doc

 

[pyplynr]

Re: Anyone know the throat dimension for a 284 win?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: geargrinder</div><div class="ubbcode-body">I'm confused by your base to ogive measurements changing so much. They are usually very close to each other.

The ogive is supposed to be about where the lands engage the bullet. The distance from there to the base is a constant. </div></div>

It's hard to get a good measurement b/c the only thing in the case mouth is the boat tail part of the bullet, so it kinda wobbles around. If I were to seat a bullet to the lands there would be very very very little, if any, case neck to bullet contact.

 

[300sniper]

Re: Anyone know the throat dimension for a 284 win?

did they specify a throat length when you bought it?

with my reamer, i'm about .020" off the lands with a 175 smk loaded to 3.1" oal. it works really good there but then again, i haven't tried any other lengths.

 

[pyplynr]

Re: Anyone know the throat dimension for a 284 win?

No, It was in stock with the middleman. I was told it was "chambered in 284 win with an 1/8 twist". Nothing more than that. He told me that the barrel company does all the work, so that their warranty will be valid. I don't know if there is any 7mm bullet on the planet that would need that long of a throat?

 

[300sniper]

Re: Anyone know the throat dimension for a 284 win?

that is pretty long but unless something otherwise was specified, i'd shoot it and see what happens. long throat doesn't automatically mean that it won't shoot great. touching the lands doesn't automatically mean that it will shoot great.

 

[sandwarrior]

Re: Anyone know the throat dimension for a 284 win?

Before I shot it I would call the middleman or Shilen and see what the standard throat is supposed to be. That barrel may be throated for Berger 180's or Matrix 190's.

If you shoot it, then you can't return it. Better to find out and make your choice now before you don't have a choice.

Are measuring this with the bare barrel or did you install it? If you installed it, check headspacing.

 

[pyplynr]

Re: Anyone know the throat dimension for a 284 win?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sandwarrior</div><div class="ubbcode-body">Before I shot it I would call the middleman or Shilen and see what the standard throat is supposed to be. That barrel may be throated for Berger 180's or Matrix 190's.

If you shoot it, then you can't return it. Better to find out and make your choice now before you don't have a choice.

Are measuring this with the bare barrel or did you install it? If you installed it, check headspacing. </div></div>

Planning on calling when they open. It was checked with a bare barrel

 

[pyplynr]

Re: Anyone know the throat dimension for a 284 win?

Ok, I may end up having to send my barrel back to Shilen. If they ask for a dummy round, which bullet should I use? 180 gr berger, 175 SMK or the 162 Amax? Should I use the longest one that way I can shoot all 3 without any problems?

 

[geargrinder]

Re: Anyone know the throat dimension for a 284 win?

Have you checked to make sure the modified case is going all the way into the chamber. It's fairly common for the modified case neck to be a bit too large for the case to enter into the neck area of the chamber.

Take the extractor out of your bolt head (careful of the detent ball launching into the outer atmosphere). Run the modified case and bullet in with the bolt. Remove the bolt then screw in the rod part of the gauge. Then see if you get some different readings.

 

[geargrinder]

Re: Anyone know the throat dimension for a 284 win?

How about an update?

 

[pyplynr]

Re: Anyone know the throat dimension for a 284 win?

Just got back my bbl from Shilen. I would have had it back sooner, but while it was there I had them thread the muzzle for my suppressor that I'm waiting on the form to come back on. They shortened the bbl a little and recut the chamber a little. Barrel is perfect now! A 175 smk @ 3.1 oal has a .016 jump to the lands.

 

[300sniper]

Re: Anyone know the throat dimension for a 284 win?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pyplynr</div><div class="ubbcode-body"> Barrel is perfect now! A 175 smk @ 3.1 oal has a .016 jump to the lands. </div></div>

that sounds like a good place to be. that is real close to how my .284 reamer is ground.

 

[Graham]

Re: Anyone know the throat dimension for a 284 win?

At 3.116 OAL I am just at the lands with a 180 JLK.