seating depth aggravation

[MildBill]

I have been working on getting some loads worked up for my 223. The purpose of these loads is for varmint and coyote shooting.

As I understand it, the bullet should be seated at least the diameter of the bullet into the case.

I had been seating them a lot less than that was more concerned about distance from the lands, and some how it slipped my mind (brain phart) to check they were at least a bullet diameter in. was getting some minor flyers, say in a group of three one would be less tight than the others.

yesterday evening while loading I checked and found out did not have them seated a bullet diameter in. When I do that they go from 0.020 of the lands to 0.085 off the lands...

figured maybe that might fix the flyers if the shallow seating had caused some concentricity problem

shot groups today and the flyer problem got much more pronounced.... grrrrrr

I do not believe the flyers are necessarily dut to the monkey pulling the trigger as I was shooting two other rifles, switching between groups to allow barrels to cool, and the other two were not throwing flyers.

so what advice can you share on seating depth regarding bullet diameter etc.

 

[22BRGUY]

I think seating bullets into the case at least the diameter of the bullet is what you will read in many reloading manuals. They have to suggest this because of all of the various dimensions of rifle chambers out there to keep themselves on the safe side of pressures with a load they state as safe in any rifle. I think as you read posts on this site, you will see that many shooters "bend" the rules a little in their quest for accuracy. In your particular rifle, there may or may not be some room to "experiment" safely. JMHO

 

[mao0720]

I can promise you that on several of my rifles I do not have the bullet at least a diameter in the case. On my FT/R rifle I have about 0.15 in the case so really about half a bullet diameter. I think you'll be fine going back out to your .020 off the lands, and if you can, try to stretch it out even further maybe .010 off. Id draw the line at about 1/3 diameter in the case. I wouldnt go less than that.

 

[Lapua40X]

Well, in truth, it's all relative. If you're loading a .223 bullet (think 6BR) for example, the length of a 107 grain Sierra Match bullet is approx. 1.223 inches. Seating it half its diameter into the case neck would put it closer to the lands than a 75 grain Nosler seated the same distance into the case because that bullet measures about .873 in length. The 107 grain bullet would be .35 inches closer to the lands than the 75 grain bullet.
Always consider the relative characteristics of every component in the reloading process when making decisions based on the experience of other shooters. It's easy to overlook seemingly minor details that can dramatically affect comparative results.
Bottom line: You can't serve both masters at the same time because seating depth and clearance to the lands (COAL) are interdependent.

 

[BoydAllen]

IMO you are "letting the tail wag the dog" If the bullet is in the neck far enough that it is not moved by normal handling of the ammunition, that is enough...period. On the other hand, seating depth relative to touching the rifling is extremely important to obtaining best accuracy, if the rifle is any good. Stop worrying about the wrong thing.

 

[MildBill]

thanks for the feedback.

I will go back to what I was doing and try to figure out how to tighten things up

 

[FeMan]

My .204 was throated so long that I have less then 0.100" of bullet in the neck with the longest bullets (Bergers) seated into the lands. Some of the bullets I tried would actually fall out before I could get them chambered, so they are a no-go. The seating bothered me for a while but since the rifle is a single feed and shoots bugholes, I have gotten over it.

 

[Shynloco]

IMO you are "letting the tail wag the dog" If the bullet is in the neck far enough that it is not moved by normal handling of the ammunition, that is enough...period. On the other hand, seating depth relative to touching the rifling is extremely important to obtaining best accuracy, if the rifle is any good. Stop worrying about the wrong thing.

+1. Besides, there is no guarantee that seating bullets into the lands will provide you better accuracy. Bullet seating is only one part of the equation. Each rifle is different and from what I've been able to determine over the years is that the whole notion of seating bullet depths came about from reloaders testing seating depths on their custom built rifles (or chambers) and not on "general production rifles". Now I've had success with seating bullets into the lands or just off the lands with some "general productions" rifles, while others have produced some of the worst shooting loads I've ever encounter in more than 40 yrs of shooting weapons of all sorts and types. Bottom line, is that it takes systematic testing to find what your particular rifle likes the best. So take your time and don't assume because a specific seating works well in one rifle that it will work well in another. That only leads to HUGE frustration.

 

[BoydAllen]

+1 especially with factory barrels
Some of their chambers are reamed with multiple reamers, and some without pilots.

 

[jlow]

I am certainly no expert on this but I will share my thoughts on this with you.

First, if you are reloading a round for varmint and coyote shooting, you might consider reloading to mag length instead of into the lands. When people seat bullets close to the lands, they are reloading rounds for single loading into the rifle – a round that requires single load does not seem to be the best solution for varmint and coyote shooting.

A round that has bullets seated close to the lands is usually too long for mag loading and even if you could by some miracle do it, having the neck grip the bullet less than a caliber diameter does not give it much grip to handling the jostling that a round would experience being loaded from a mag even if it is a bolt gun. Many bullets jump well and does not require seating close to the lands – 175 gr SMK is a good example

In my experience, the further out you seat a bullet and the less bearing surface the neck and hold on to the bullet, the easier it is for the round to have concentricity problem. It can surely be done but really in practice only by the guys who shoot at a range where conditions are more conducive to careful handling of the rounds.

 

[BoydAllen]

I have a Winchester .222 that has a magazine, and the action length is sufficient to load into the lands, but the magazine cam blocked for the older style of bullets and would not allow the loaded length that gave the best accuracy (.006 longer than touch) with the 40 gran Vmaxes that I prefer to use in the field with this rifle, so we drilled out the spot welds that secured the magazine block, and relocated it far enough back to allow for the plastic tipped bullets. For those rounds, I think that I have about .150 in the neck, and because I am shooting out of a magazine, and realize that this puts bending forces on the bullet as the round feeds, I run enough neck tension so that is not a problem, the necks are unturned, and the best groups (sporter weight factory barrel) are five shots in the high 2s to low 3s.

In the case of the OPs 204, I would guess that it may also be built similar to mine, with a blocked magazine that could be modified, since most short actions are built to take loaded rounds of up to 2.8" in the magazine, with no block.

Thinking back, the other thing that I had to do was to modify the bolt stop to allow the bolt to open far enough to pick up rounds from the lengthened magazine.

 

[jlow]

Thanks Boyd! I guess one can certainly go to heroic lengths to do this, but it would seem that unless on knows that mag length or shorter stuff does not fit the bill, seating close to the length would not be the first thing to try?

 

[BoydAllen]

I would go looking for accuracy, and then deal with the magazine situation as needed. I do not view what we did to my duce as anything difficult or unusual, just part of getting the most out of my hobby. Half the fun is making things work better. IMO most fellows get a little lost working up a load because they don't use a systematic, efficient approach.

 

[MildBill]

just a little follow up on the 50 grain bullets I have been working with

when seating the bullets 0.030 from the lands I have them about 0.166 into the casing, which is about 74% of the bullet diameter.

I am thinking one possible solution to get a little a little more bullet into the case is to do some measuring and use 55 grain bullets. little bit longer should have a little more bullet to go into the case, and for what I intend to use them for probably hard to notice any difference between the 50 and 55 if I can work up a good consistent accurate load.

 

[amlevin]

+1 especially with factory barrels
Some of their chambers are reamed with multiple reamers, and some without pilots.

Are you talking about Remington's? I have one that if I seat a 175 gr BTHP to touch the lands the boat tail portion is all that's in the case. Funny thing though, it shoots <.25 MOA when jumping from Mag length (over .100")

 

[Webster]

What kind of rifle are you shooting? I have a Rem 700 BDL with a 6mmBR Kreiger barrel. I have to clean the bore after about 15-20 shots or I get fliers. Check the bedding by seeing how far you can pull a dollar bill between the forearm and barrel. Just because it's a quality bullet doesn't mean it will shoot well in your rifle. Shoot a ladder test. If I do my part and it isn't windy I can shoot groups close to 1/4" with 68-70 grain bullets only about 1/3 into the neck. The rifle doesn't know what half way in the neck is. That theory probably exist because some shooters found better results. I have a 0.065" freebore. With the bullet 0.010" off of the rifling I am 1/3 down the neck. Don't worry about rules just find out what shoots nice groups on the target. Some benchrest quality bullets don't consistently shoot small groups in my rifle. My rifle seems to like Sierra 70 gr BlitzKings and Hornady 65 GR VMax which is ideal since it's a GH gun and not for competition. Whenever I get a flyer I think it's about a 90% chance I did something wrong. It's hard to hold a factory stock perfectly still on a sandbag and I don't have a good trigger pull. I just showed my rear bag to a very good 1000 yrd shooter. He said the rifle was sitting to high in the v groove. So I have to somehow reshape my bag to fit the stock. By a flyer how far outside of the group are you in inches? Have someone else shoot the gun.

 

[MildBill]

this particular rifle is a rem 700 stainless sps sporter that I put in a stocky's hart aluminum v-block laminated wood stock. Barrel is floated. Trigger is a timney set at 2.5 lbs.

it gets cleaned about every 20 shots give or take a few, or if I change powders.

I use patch out with accelerator, and also use boretech stuff every once in a while too, especially the c4 stuff for carbon if it appears, based on the patches, there is some in there being stubburn, depending on the powder mainly.