Hello Members: I am interested in any opinions concerning which rifle manufacturers produce rifles with 'reasonable' (i.e. shorter) throat lengths versus those that gives us long throats for 'our own protection.' Thanks in advance.

pagris,

Almost all manufacturers have the same throat length. They use chamber reamers that have the throat incorporated in the reamer. The reamers are usually to SAAMI standard. The only difference you will see is within the tolerence span.

Headache

My newest Remington 700 has a long throat, much longer than the 700s I bought from 5-10 years back. Most of the newer rifles have longer throats and w/ alot of loads you can forget about reaching the lands if you want em' to fit in the Magazine.

Reloader

Is there a SAAMI standard for throat length or angle? I don't think so. We're actually talking about two different things here. There is freebore (or Leade) and there is throat. The leade is the unrifled portion of the bore immediately in front of the case neck and is usually groove diameter. The throat is the tapered transition from leade to bore diameter. The freebore and throat depend on the bullet being used. For example, back when the Rem 244 and the Win 243 were first introduced the Rem was based on a light weight varmint bullet while the Win was based on a much heavier hunting bullet. The freebore and throat of the two rifles was completely different. The Rem had almost no freebore and a very high angle throat while the Win had a little freebore and a low angle throat. The newer Rems do indeed have a longer freebore/throat than they used to.

Ray

Cheechako,

Yes, SAAMI chamber standards include the dimensions for the throat and any freebore if required. A chamber reamer will have the entire chamber ground to spec.. This is required so that standard production ammo will be within the pressure requiements. If you have a shorter freebore or throat (forcing cone, ball seat) your pressure my spike to a dangerous level.

The variation you may be seeing could be between the min and max dimension allowed. This is .002" which when calculated using an angle of about 1 1/2 degrees would allow quite a bit of lenght variation.

Headache

Headache

Thanks for that info. So how does SAAMI determine the leade and throat dimensions? Do they take the longest commercially available cartridge on the market and use that as a standard? By "longest" I mean the heaviest bullet seated out to max length. SAAMI is a really exclusive club and doesn't give out any information, except to members. Is there a way to break into their ranks?

Ray

I'm not wed to one manufacturer, so end up owning/loading for a variety of rifles. Some end up having long throats, others end up having short throats. I have read that the manufacturers start their reamers out at max SAAMI specs and use them until they wear down to min SAAMI specs before replacing. This makes sense to me. If you have a rifle built with a new reamer, the chamber/throat will be on the max size.

-Lou

A more appropriate question, or at least one that goes hand in hand with the one posed is:

What manufacturers give you enough magazine length to enable seating close to the lands?


Without guns we are subjects or victims, with guns we are citizens

Cheechako,

The chamber design is established by a member company and submitted to SAAMI. The company determines which bullets they want loaded for that particular new caliber they have designed. Other ammo manufacturers may decide to load for a new caliber, but it is their responsibility to manufacture ammo that meets the design specifications.

SAAMI is an organization of manufacturers who create ammunition and chamber standards to insure uniformity between manufacturers. This information is proprietary to the members. The same as if you were to call up a company and want a set of prints to manufacture their product.

SAAMI has made information available to the public in the form of ANSI standards which can be purchased by anyone.

Hope this helps,
Headache

Good Point Woods, I will say that the Remingtons do have plenty of clip length despite their long throats. My Savage 16 300WSM has a very short clip length, almost to the point where you would think it is dangerous (By that I mean I have to seat some bullets like NBTs and Accubonds so deep the bullet base is deep in the case and just looks funny).

The Weatherby rifles I load for have a pretty tight clip length although, I'm pretty sure that's the point since "Free Bore" is one of their main characteristics.

Have a Good One.

Reloader