How to deal with a very long throat?

[119er]

I have a Rem 700 in .30-06 that I inherited from my grandfather when I was a kid. The rifle is mid 1970's production, or thereabouts I believe, and it is an ADL in gloss finish and iron sights.

Anyway, he never really hunted much with it and it was used mostly for pest control on his land. Since he passed in 1993, it has probably seen maybe 60-80 rounds down the barrel fired by me so the chance of it being worn out are very slim.

The rifle never shot very well at all with factory ammo. When I began to reload I cleaned it very well with copper solvent and began trying to work on a load for it. Just checking around with different bullets on hand at the time I tried a Hornady 150 FMJ in an OAL gauge(kind with drilled/tapped case). The 150 was not even in the case by the time it touched the lands. Only a small portion of the boat tail was in the mouth. I tried a 168 SMK and only about 1/8-3/16" of the bearing surface was in the mouth of the case. Not that I intend to load to the rifling, but it is a good indicator of what is going on. So I loaded some 168's, seated them longish, new Leupold scope and it grouped poorly. This was several years ago, hence lack of detailed info.

Now I am thinking of round two. Any suggestions about where to start to make it shoot? I've thought about maybe really heavy 200-220gr round nose bullets. I'd like to make it shoot at least 2-3" at 100 which it has never done.

 

[morcey2]

What kind of groups were you getting with factory loads? How does the crown look? Have you had anyone else shoot it? I doubt that a long throat would be the only cause of 4"+ groups.

Matt

 

[Haxby]

Have you ruled out other possible problems, like a bad scope, or loose mount, or bad stock bedding?
I've shot 100 gr Speer plinkers in an '06 with fair accuracy. No idea how far from the rifling they were.
On the other hand, I don't see any reason not to try long bullets. Hornady and Sierra make 220's. COL will probably be limited by the magazine length, unless you want to single load them.

 

[steve4102]

Rem 700 have always had long throats as far as I know.
A long throat is not going to aromatically turn a rifle into a Non-shooter. Many a rifle have long throats and can be made to shoot just fine or even better.

Start your load development with a bullet known for accuracy, Ballistic Tip, Sierra, Etc. and a bunch of different powders, work your way up until you find a great load.

As already pointed out, check out the physical side of the rifle and optics. Might want to switch to a proven scope to getchya started.

Also the Rem 700 has a pressure point at the fore-end where the stock puts pressure on the under side of the barrel. I personally have removed these and free floated all my 700's. YMMV

 

[Slamfire]

The 168 grain target bullets are relatively jump insensitive. You are simply going to have to shoot different bullets and powder combinations till you find something that works well.

 

[shooter1niner]

You didn't mention the load you are using. I like 45 gr. IMR 4895 with Hornady 165 gr. flat base. This is a pretty mild load and shoots into an inch at 100 yds. from my rifle. I'm a little (.020) off the lands and not near the cannelure at all. Cartridge fits the magazine.

 

[gamestalker]

Wow, that's a super deep throated barrel. I've been loading for numerous 700's for quite a number of years, some as old and even older than that one, multiple 30-06's also, have never come across a throat that deep.

Is it possible that the bullets are pulling back out of your gauge when you open the bolt, or when you pull the case out?

Maybe try something as follows, to see if indeed everything is as it appears. First make sure you have a piece of brass that will fall out of the chamber by gravity alone when you chamber it by hand, with your fingers, barrel pointed straight up.

Then try seating a bullet long, then insert the cartridge into the chamber by hand, not using the bolt, barrel pointed straight up. If when you jam it into the chamber it sticks, then you know you are contacting the lands and can then work from there to find a suitable OAL. If it doesn't stick, then you know you do indeed have a deep throat.

But even if it is a deep throat, this doesn't mean it won't shoot well. just try different OAL's, bullets, and powders until you find a load it will shoot well.

GS

 

[joed]

The biggest problem I found with that vintage 700 is the wooden stock. If the barrel isn't shot out get it bedded, you'll see an improvement.

 

[allaroundhunter]

My 700 has the same problem. I was able to get it to shoot SMKs well, but I want to be able to load bullets closer to the lands so I am in the process of switching barrels.

 

[243winxb]

long throat & OAL

I like to start with the bullets base at the neck/shoulder junction , if possible. If the bullet has little contact with the neck when trying to reach the rifling, bullets may become crooked when contacting the feed ram on chambering the round. On firing, the bullet may move before pressure is high enough to burn the power correctly. This is because of light neck tension when the OAL is to long. This happens sometime, when using slow burn rates of powder in larger Weatherby type rounds. . Accuracy can be very good with the bullet jumping to the rifling in a factory rifle. In the 30-06 use IMR or H 4895 with good quality bullets from 150 gr to 180 gr. No FMJ bullets.

 

[morcey2]

Most of my rifles have throats that make the one in your 700 look downright stubby by comparison. I have a Spanish M44 that has a throat so long that I can't load even bullets as long as 200 gr Partitions anywhere near the lands and have _any_ part of the bullet in the neck. There's about a 1/16" gap between the bullet and the case. It wasn't shooting well at all. There were 2 things that made it shoot well:

1. New Crown. The crown was dinged up ever so slightly. Before touching it, I was getting 6-8" groups at 100 yards. As a last-ditch effort before rebarreling, I recrowned it with a lee case trimmer and a brass screw. Groups dropped to 2-2.5".

2. Lee Factory crimp die. I started giving the bullets a medium-ish crimp (3/4 turn after contact) and the groups shrunk to about 1" consistently. I can load a bunch of the best loads uncrimped and the best loads crimped, have the gun loaded without me knowing which set is in, shoot it, and tell which one it was from the grouping.

This is all with an old milsurp barrel that wasn't taken real good care of before I got it. It is somewhat frosted, but it shoots extremely well, at least with partitions and Speer 200 gr Hot Cor. If you've eliminated everything else, try the FCD. It doesn't work on everything and it probably won't help on something with a short throat and relatively tight chamber. It has helped on the aforementioned 8mm, one of my 7x57s, one of my 1903s, and most of my mosins. It didn't matter or made things worse on the other one of my 7x57s, the other 1903, and my 257 Roberts.

I would be really surprised if its lack of precision has anything to do with the throat. As others have mentioned: bad scope or loose mounts/rings, bedding issue, and the crown are all suspect until proven otherwise. Something else to look at would be a weak firing-pin spring giving inconsistent ignition (not likely). If the scope is too high for the stock and you can't get a good cheek weld, that can cause issues. A bad rest can also cause issues (personal experience). And don't shoot for groups using FMJ ammo. I load lots of 150 gr FMJ for my 1903s and Garand and it consistently groups much worse than even average hunting bullets. But they're cheap and accurate enough for making life miserable for 2-liter bottles of soda.

Regardless of your own skill level, have someone else who you know can shoot shoot the gun and see what it does. It could be as simple as flinching or anticipating the recoil.

Just more of my thoughts.

Matt

ETA: If the trigger isn't nice and crisp or is too heavy, that can also cause grouping issues, but probably won't cause 4"+ groups by itself.

 

[OYE]

Deep throat

You probably have more than one thing going on.

I have a Remington 721 with a relatively deep throat, that was shot very little by the original owner. It does not like most boat tail bullets. One brand in particular (that I had had great success with in a different rifle) would not consistently hit a 16 inch square target at 100 yds. Flat base bullets would generally group 2 inches at 100 yds. It seemed to like Remington core locks
the best. Seating depth didn't seem to matter. We did bed the action and float the barrel with no improvement. The scope and mounts were not an issue.
Several years ago I got the time to try to resolve the matter. After about 12
fouling shots, the rifle will group the flatbase corelocks inside an inch circle with the best being .317 inch center to center at 100 yds ( these bullets were seated to the cannelure with a lee factory crimp). It will continue to group tight for at least 20 more rounds which is where I stopped. I did find one
boat tail bullet that would group about 1 1/2 inch out of a clean bore, but it was not suitable for hunting. The gun does group the accelerators sub inch
at 100 yds from a clean bore.

We have known of other rifles that crop up from time to time with similar symptoms, in particularly not liking boat tail bullets, and some brands of flat base bullets not shooting that well either. They did all have long throats. But
many guns that have long throats are tack drivers, so we always figured it had
to be a combination of a long throat and something else. But we didn't know what for a long time.

A few years back we started talking to the tech guys at the different bullet manufacturers and didn't get any ideas till we got to the Sierra guys ( the Bulletsmiths). According to their database and chamber castings over the years,
they determined it was a combination of a long throat and an oversized throat.
Has to be both.
Anyway they recommended sticking to flat base bullets. OYE

 

[119er]

All good recommendations. The crown looks fine, the rifle looks practically new minus safe dings. I switched to the Leupold scope originally because I thought the same vintage Bushnell Banner was bad. I'll have a look at the stock. It is in nice shape, has pressed in checkering all over it. I've upgraded my bench equipment since I last played with it and have better accuracy skills as well. I might get some flat base bullets and try that. Come to think of it, I have a 700 in .223 that really prefers Sierra flat base 52gr over the 53/55gr boat tail.

 

[ArchAngelCD]

Just because the bullet isn't near the rifling doesn't mean the rifle won't be accurate. Look at the Weatherby rifles, all have long throats but Weatherby rifles are known for their accuracy.

What loads did you try? What bullets/powders/primers did you load? What factory ammo have you shot? I have found a 168gr match grade bullet over a charge of 57.0 to 58.0gr H4350 set off by a CCI LR primers is accurate in every 30-06 rifle I have shot. I use the same charge over a 165gr hunting bullet with similar results. (usually a 165/168gr Sierra GameKing and MatchKing bullet)

More info please... I can't see a fine old Remington 700 not shooting well.

 

[gamestalker]

I have two older ADL's, one in .270 win, the other an 06, both have wood furniture, and both shoot very accurately. I bedded both, floated the barrels, and lapped the lugs. These little simple tune jobs are often the little nudge that will get most production rifle's shooting decently. And honestly, I would spend some time trying a couple more load combinations along with some simple tuning. I'll bet that old 700 will group nicely with a little bit of inexpensive DIY tuning.

GS

 

[homatok]

The following may be of some help, if you want to know what the real dimensions of your chamber/leade/throat are. I copied this from a posting from the Cast Boolits site, submitted by member Goodsteel. The pictures did not copy, so if you want to see you can go to that site and do a search for How to do a pound cast. Hope this is of some use to you.



FYI This is how I do a pound cast.



What is a "pound cast" you might ask?
A pound cast is a way to produce an accurate rendering of the shoulder, neck, throat, lead, and rifling of your barrel.
This information is key for choosing a boolit design that fits your particular chamber properly. In fact, there is no other way that gives an accurate enough rendering of these key areas.
The down side is that if you do this wrong, you are going to be talking to your local gunsmith, or performing operations to get the slug out of your rifle that could really mess things up!
As it happens, I have a rifle that needed a pound cast to be performed and I took pictures of the process so that you can see how to do it, and not jack up your rifle in the process.
Pay attention to these instructions carefully, and don't cut corners! The first time I did this, I used what I had on hand, and stuck the slug in my barrel and ended up having to drill it out in order to prevent turning my rifle into a really heavy boat paddle.

The materials needed are as follows:
1. pure lead
2. a piece of brass
3. a common hammer
4. a steel rod slightly smaller than your bore
5. a gas check
6. a boolit mold a little on the heavy side for caliber
7. a propane torch
8. a ladle
9. patience and common sense

The first step is to clean your chamber and barrel, and oil it lightly.
Next, you select a piece of brass that you don't mind losing. Melt some pure lead in your ladle, and pour it into the piece of brass up to just past the shoulder.
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Take your propane torch and heat the neck of the brass till the lead melts and forms a clean, level surface. This does two things, first, it aneals the neack of the brass, and it also gives a good level stop for the slug.

Second step is to preheat a mold, and cast a boolit out of pure lead. Take your needle nosed pliers and flare the case mouth so that you can easily seat the boolit in the case with a couple light raps from your favorite problem solver.
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Next, slip the "slug cartridge" into the chamber and close the bolt on it.
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Now, set the rifle aside, and grab your steel rod. In this case I was doing a 30 caliber pound cast, so I was using a 1/4" steel rod.
Wrap masking tape around it thusly to protect the bore and the crown of your rifle:
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make sure that the end of your rod is square and has no chamfer on it. You want a sharp, square end on the rod.
Grab a dab of grease and wipe it on the tip of your rod like so:
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This will keep the gas check in place and insure that you get it started correctly.
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Next, place the GCed tip of the rod on the muzzle of your rifle, and tap it past the crown and down the bore til you feel it contact the boolit.
Now, this is critical. I don't know if you can see it here in this picture, because I have a flash hider on this rifle, but there is a band of tape, perfectly positioned to protect the crown of the rifle from damage as the rod is being pounded. You might want to make sure that you have this right.
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Tim Malcolm