bullet seating depth?
 

Is it a general rule to seat the bullet to at least a depth equal to the diameter or the bullet? thanks

RE: bullet seating depth?
 

From what I have read, that is the general rule.

RE: bullet seating depth?
 

In a perfect world . . . the base of the bullet is seated even with the base of the neck - the front of the bullet is about .010 back from touching the rifling - and the loaded round fits in the rifle's magazine.

RE: bullet seating depth?
 

Agree with Roskoe! This way it keeps the free bore to a minimum, but safe.
I find that Weatherby ammo is seated to much and has excessive free bore.
The bullet has to jump to far to print on rifling and will not print straight.
Best to reload any factory ammo with with excessive free bore, backing off
.10 or untill it clears the magazine. There are other ways to do this, but I
started using the Stoney Point free bore gage. IMO, I think it's the best way
to bullet seat reloaded ammo.I use the Redding Bench Bullet Seater and set it
at .10 under bullet/rifling contact and adding .001 till it clear's the magazine.

RE: bullet seating depth?
 

Another technique from yesteryear that is coming back in the riflesmithing world is the grinding of chamber reamers without a throat. So the reamer cuts the body, shoulder, and neck. Then, as a second step, you cut the throat with a throating reamer - custom tune the throat length to a specific bullet/seating length. Many of the old reamers from P.O. Ackley's collection at the Trinidad Gunsmithing College are cut this way.

RE: bullet seating depth?
 

To answer all your answers go to the may issue of Rifle Magazine and read the study done by the EXPERTS at Nosler on this subject gentleman. vangunsmith. You might learn something. I thought id let you read it for yourself,rather than tell you. vangunsmith

RE: bullet seating depth?
 

I loaded some Barnes 180 gr. XLC's for a .300 Win. Mag., and the instructions in the box stated, "one should seat the bullet's shank in to the case's mouth at least 2/3" of the bullet's diameter". Good luck.

RE: bullet seating depth?
 

thanks for the information. the seating depth question arose because I have a long throated rifle. When I try to load close to the lands it would leave very little of the bullet in the neck. was wanting to know what the least bullet depth in the neck is required? thanks

RE: bullet seating depth?
 

Seat the bullet far enough out so that it will reliably cycle through the action and fit in the magazine. Otherwise you'll have feed problems or a single shot. The accepted standard is at least the diameter of the bullet, although we all know how that goes on some guns.

RE: bullet seating depth?
 

One diameter deep is a rule of thumb.....there's nothing sacred about it.....more or less is up to you and will work fine.

RE: bullet seating depth?
 

As long as the bullet doesn't fall out, your deep enough.

I've gone to a heavier bullet at times when I couldn't get as close to the lands as I wanted. Only when I wasn't getting the accuracy I wanted though. I don't care if the bullet is a quarter inch from the lands if it groups well (which it wouldn't!)

RE: bullet seating depth?
 

I have fired rifles that did group well with the bullet seated .200" to .250" from the lands.

RE: bullet seating depth?
 

My 300RUM right now is seated .2" away from the rifling. I have also found some bullets like the Grand slam can be made to shoot well with it .25" away from rifleing instead of up close.

RE: bullet seating depth?
 

That mlight be good if a person only used one type bullet all the time.the reason at times was not to have the throat cut on the reamer was that some people hogged off to much at one time when chambering and broke the reamers pilot off. Thats why they came out with other than solid pilots. One has another problem cutting the throats ,and have them centered after already cutting the chambers. vangunsmith

RE: bullet seating depth?
 

Van - your post doesn't make any sense to me. Maybe that's my fault . . . . but I have chambered quite a few rifles over the past 30 years. I currently own 67 chamber reamers - all have been used a least a couple of times - some have chambered over 100 rifles. The pilot, whether floating or solid, guides the reamer into the bore of the barrel. The floating pilot reamer holder gives the reamer the ability to track right down the center of the bore. And the barrel shank is centered, trued, and spinning perfectly on center when all this occurs. The chamber reamer is going right down the center of the bore, whether it is cutting a throat or not. And if you cut the throat a second step, the piloted throating reamer is going right down the center as well. This would be hard to screw up, unless you have been drinking! With all due respect, what am I missing here . . . .

RE: bullet seating depth?
 

That's interesting. I have a new 6.5x284 rifle for benchrest. The figures are for lapua brass and scenar 139 bullets:

Bullet Length 1.370"

Bullet diameter 0.264"

The minimum Cartridge Overall Length from Lapua reloading tables is 3.11"


So, by using the general rule 1.370 - .264 = 1.106" of bullet should be sticking out of the case and 0.264 should be seated in it.

Mine, however, has about 0.50" (nearly twice as much as the "rule of thumb") in the case when touching the lands and about 0.87" sticking out of the case. It is also very close to the minimum COL.

It hasn't been fired yet. Do you reckon I should get a little more freebore reamed out before I do fire a round, say around another 0.2" so I can seat the bullet a bit further out?

Thanks

Robert

RE: bullet seating depth?
 

IF freebore is cut correctly(regardless of others opinions IMHO) the bullet can still have a large jump and be extremely accurate(for reference purposes here I'm talking MOA or just under as extremely good hunting rifle accuracy). Its just that the free bore should be close to bullet diameter.

In your instance of having or wanting to seat way out, you can try varying the neck tension to see if that may help your grouping. Redding makes good dies for this or Jim Carstensen can adapt the size die you have. In this instance neck tension will be about the only way to help hold onto that bullet really well if its needed.

Going the other way in seating, its best not to seat below the neck/shoulder juncture BUT only because there can be a donut that will destroy accuracy hiding down in there. If thats reamed out then it will have little affect on accuracy.

I'm curious as to the rifle article, but I don't have access to the article unless someone can help me. And I despise someone posting you are all wrong due to this one article..... Let us know what it says and back it up a bit. Just because I read it doesn't mean I believe it.

Prime example is folks listening to bullet makers that claim that lead tips melt off bullets in flight. I've got enough proof that they do not melt, while others claim they do. Their only claim is from what they are told. There is too much evidence to the contrary to believe that. Not to mention required energy calculations(that are beyond my capabilities but have been presented)

Final thoughts on seating depths. There is no guarantee. ONe thing to be aware of is that seating just to touch will create varying speeds and pressures due to the fact that you each bullet can be a bit different and instead of just touching, some will be jumping, some engaged to the rifling. Some just touching. So the best rule I can give you use a minimum of 10th off or 10th engaged and go from there. Don't be in between. I've won lots of matches with engaged rounds. But then again I've won a lot of individual matches with bullets that jump a LOT. In hunting rifles I feel one should be a minimum of 15-20th off for safeties sake.

Jeff

RE: bullet seating depth?
 

IF freebore is cut correctly(regardless of others opinions IMHO) the bullet can still have a large jump and be extremely accurate(for reference purposes here I'm talking MOA or just under as extremely good hunting rifle accuracy). Its just that the free bore should be close to bullet diameter.

Yes, Iagree. I think mine has been cut about 200 thou too short though. Look how deeply the bullets are seated. Over twice the length of the neck.

In your instance of having or wanting to seat way out, you can try varying the neck tension to see if that may help your grouping. Redding makes good dies for this or Jim Carstensen can adapt the size die you have. In this instance neck tension will be about the only way to help hold onto that bullet really well if its needed.

No I can't set the bullet further out. It hits the lands even when deeply seated in the case. That's my problem! That's the point I'm making.

Going the other way in seating, its best not to seat below the neck/shoulder juncture BUT only because there can be a donut that will destroy accuracy hiding down in there. If thats reamed out then it will have little affect on accuracy.

Well, I am a long way further in than the neck/shoulder juction. About 0.25" in fact. I cannot do anything about that because the bullet is touching the lands already. Assuming no donut, how far into the case can the bullet go. The scenar 139 grain is a long bullet. Over half of it is in the case even when the other end is touching the lands.

I'm curious as to the rifle article, but I don't have access to the article unless someone can help me. And I despise someone posting you are all wrong due to this one article..... Let us know what it says and back it up a bit. Just because I read it doesn't mean I believe it.

I have no idea where it is. Sorry :(


Final thoughts on seating depths. There is no guarantee. ONe thing to be aware of is that seating just to touch will create varying speeds and pressures due to the fact that you each bullet can be a bit different and instead of just touching, some will be jumping, some engaged to the rifling. Some just touching. So the best rule I can give you use a minimum of 10th off or 10th engaged and go from there. Don't be in between. I've won lots of matches with engaged rounds. But then again I've won a lot of individual matches with bullets that jump a LOT. In hunting rifles I feel one should be a minimum of 15-20th off for safeties sake. [/quote]

Yes, but my problem is that I think my bullets are seated far too far into the case. I cannot move them out because they are touching the lands. i.e. the throat is VERY short.

There is nothing I can do about it, other than ream some more space. I think?

RE: bullet seating depth?
 

Robert

I'm sorry. I forget this thing replies to the last person that posted. None was directed at you. Just general thoughts.

FWIW in your case are you sure you are touching rifling or are you touching the throat? I had a very similar issue in where I thought I had the chamber designed a certain way. It was. Found out the bullets I was using were .0003 larger than others I was using and I was reading off the sides of the throat. Its why I never got a pretty rifling mark either. I just shot that rilfing the way it was supposed to be.

If I were you, I'd find out what the exact chamber dimensions were and at what length you should be able to seat the lapua bullets.

If in the end the throat needs to be longer it can be cut.

Jeff

RE: bullet seating depth?
 

No, I don't. Your in a good situation. Yes, its further in the case than your use to, but different bullets will seat different ways.

How does matchkings do? Or typical hunting bullets?

RE: bullet seating depth?
 

One doesn't buy 6.5-284 Benchrest guns from Gart Brothers - a gunsmith somewhere built this gun. I would get in touch with that person and find out if he set the throat to work with a certain bullet - or, as Jeff suggests, if he used a tight spec throating reamer. You may indeed have to put a little more throat in the rifle - but once you do this, there is no going back - without setting the whole barrel back and starting over with the chambering process. I would explore what you have and what it will/won't do first.

RE: bullet seating depth?
 

If I were you, I'd find out what the exact chamber dimensions were and at what length you should be able to seat the lapua bullets.

If in the end the throat needs to be longer it can be cut.

***********************************

OK, many thanks, I'll do that.

Rob

RE: bullet seating depth?
 

*******************************************

Well it's a heck of a lot further seated that one bullet diameter. It's more that two. The deeper you seat the bullet the more possible you can create some very high initial pressures.

I only want to use 139 scenars. They are long slim boat tails with a very high BC.

Thanks Rob

RE: bullet seating depth?
 

Very true. My gunsmith built it as a bench rest rifle. He hasn't set it to work with any bullet and he has not got a OAL measurer in that caliber at the moment. He told me if was reamed very short because of that but to try it out and see if it shot OK. He thought it might be a good situation because as the lands wore he could ream new throat to make up for it and lenghten the barrel life. (Unfortunately I daren't shoot it at all since I don't know what the pressure effects of deeply seated bullets is on pressure. My gunsmith is not around to ask at this time so that's why I asked here. I wondered if anyone had ever seated a bullet so deeply into the case and if they got problems. I read one article on pistols and it bluntly said that over deeply seating bullets can blow the pistol up.

I could wait a couple of weeks and ask him.

Thanks

Rob

RE: bullet seating depth?
 

Robert

This is not the place to answer your question further. You had a gun made for BR shooting. That also means that the neck diameter may be tight, requiring you to turn the necks of your brass before firing. To fat and you run into pressure problems.

Get hold of your gunsmith and have a good talk before you go any further.

The 6.5x284 is a well known round shot by many folks. Its very common. As is your choice of a 140 grain(+/-) range of projectile. For it to be seated that deep in the case you need to fnd out more info. Don't just tell someone else to lengthen the throat. Find out why and whats happening. Its something we can't diagnose here without seeing the gun. I know. Because I was in your same shoes. There was an answer and it was not throating further. It was learning what I had and how to use it.

Please talk to your smith!!

Jeff

RE: bullet seating depth?
 

Rob

You and I posted at the same time....

I see that your smith is gone at the moment. Just sit tight. It sounds like I might also be shopping for a smith that is knowledgeable. More so than this fellow. His line sounds like BS to me. The 6.5x284 is used with your weight bullet more often than not for LR shooting. It should be throated as such. Coming back later to deepen-- hogwash. That barrel might not last 1000-1500 rounds anyway more than likely for top edge accuracy.

Yep, forgot about deep seating. I don't recall seating depths but here is an example in 223. I used to shoot 75 amax seated long for single loading in the AR. Was appx 2.450 give or take. Then i loaded up some at mag length with was way down in the case and looked ugly they were so deep. It was 2.240 oal. I did back off my charge about .75 grains basically but everything else was fine.

Take into consideration my 223 case capacity is about 25 grains, compare to yours, reduce load accordingly and for a safety measure and shoot if you have to. I still say you really need to find out the throat diameter vs your bullet or you still may be in trouble firing any rounds. Not to mention the neck diameter of the loaded rounds again either. Both are serious issues. Regardless of how bad you need to fire the gun. Its your gun, your money and your life. be careful.

And if you smith can't answer the questions go find one that knows something.

Jeff

RE: bullet seating depth?
 

Sure, you might not reach peek velocity. I got a friend who built his 300RUM with no freebore. So loaded to 3.6" COL with a 200gr matchking his was .005" from the lands. One, it shot extremely accurate, but he had to throw out the loading data on it. And couldn't reach 3000fps without pressure signs.

Hey, its gun, you not sure if you was asking for advise. But I gave my 2 cents.

RE: bullet seating depth?
 

Thanks everyone for your useful comments.

I need to speak to my gunsmith about seating the bullets and I will do that before firing it.

Kind Regards

Rob