.303 Throat Gauges

[Ovenpaa]

We all know someone with a .303 rifle, or own one ourselves. In fact I believe all new FAC holders should get out and shoot one at some point, just because. I have a modest collection of .303 Sporting and military rifles, including Lee Speed and postwar No1Mk3 commercial examples here in the armoury along with later ones such as the 1920 Lithgow below.

One thing I can usually say about the .303 rifle is it will have been shot, usually shot a lot and accuracy does suffer after a while. Now accuracy is not always a good reason to buy a rifle and I have rifles here that will not shoot a hand span group at a 100 yet they are keepers, equally I have worked with rifles capable of shooting tiny groups at extremely long distances that have left me cold.

For me, the majority of .303s are usually very special rifles and to find one that shoots is even better, so how to determine if the rifle in your hands is going to shoot? Well range time is the simple answer, however you can also check a few areas before taking the rifle out and bore and throat erosion are always good places to start. A careful peer up a barrel tells you a lot however a shiny bore is not always a good bore and if the throat has disappeared 3/4" up the barrel you are always going to chase accuracy. So I made some throat gauges for just this reason and here is a prototype and an early version.

Use is very simple, just remove the bolt and drop the gauge into the chamber. The amount of the relieved section visible gives an instant indication of throat erosion. This is not an absolute measurement and just because the throat has gone does not mean the rifle should be put back in the rack, however if you gauge two identical looking rifles and one swallows the gauge you know which one to shoot first.

So there you go, one small area to check when considering a .303 purchase. I should probably sit down and write a book of such tips however not all of them are going to interest people.

....so why am I telling you this? Because you need to know.

[WelshShooter]

A good post and some interesting insight. My No4 Mk1 has obviously been enjoyed at the range as the rifling almost diminished at the last ~1 inch of the bore. However, she is pretty accurate thus far which does beggar belief on times. However, I didn't really check the bore during purchase due to inexperience, plus I had it for the low sum of £350 with dies, brass and sling and this was within the last decade so not bad at all!

I definitely agree with you though, such that if you have two identical rifles side by side going for the same price, you're more likely to have an accurate rifle if you check the condition of the crown, bore and throat. I'm interested to see what how deep the gauge goes in your collection of Enfields and whether there's a correlation with the accuracy of the rifle (eg deeper throat equals worse accuracy).

[dromia]

When I used to shoot competitively my service .303 was a Longbranch no 4* with a mis-matched bolt and 1 1/2" chronically crazed throat wear afore the rifling started and boy could that rifle shoot. Won me a few gongs in my time on the days when I did the rifle justice. Just needed to keep on top of the coppering. A good muzzle is more important than a good throat

With those "deficiencies" it shouldn't have been hitting the paper but of course then we didn't have the internet then so probably the rifle never new that it shouldn't be giving 100 yard 2" groups.

The target is the only true way of telling how a firearm will perform accuracy wise

[Ovenpaa]

The Lithgow is probably about the best barrel I have on a Lee Enfield and is virtually the same as the new barrels I have fitted in the past.I have a Lee Speed that will swallow the gauge and was one of the reasons I started building longer versions! The Lee Speed does shoot, however only with cast bullets and some very careful reloading, whereas the Lithgow shoots virtually everything I try at around 1" at 100 yards off a sand bag which I would say was good for a 1952 barrel. In-between I have a really scruffy P14 with a good throat that also shoots.

Throat condition is not a definitive reason to not buy a rifle, however add a few more reasons and it can give you a reason to either look elsewhere, or a bargaining tool :)

[dromia]

My Lee Speed sporters have sound barrels but will only deliver good condom accuracy with flat based bullets.

[snayperskaya]

My Lee Speed sporters have sound barrels but will only deliver good condom accuracy with flat based bullets.

Is that down to flat base bullets having better concentricity than the majority of boat tails?.

The throat and bore on my SVD are like new and it is noticeably more accurate with flat base bullets and those with a very short boat tail such as the .311" 150gr PPU SPBT.

[Ovenpaa]

Flat base do tend to be more accurate at shorter distances.

[kevinww]

My very late Fazerkerly No4 Mk2 shoots a treat here is its last outing straight out of the box after putting the clone No32 Mk1 scope back on it using my own mount.

[Alpha1]

At what distance.

[Pippin89]

I used to shoot a .303 with my old man when I was a kid. Just me and him up at Bisley were some of the best times of my life.

Just a thought on the gauge, would it help to turn a tiny groove every 1/8" or something so you can tell how far it has gone more easily?