Thin sporter barrel load development

[PD Gohil]

Getting ready to start load development for my Remington 700 7mm Magnum. I'm concerned because the barrel heats up rather quickly. Three shots and it's pretty warm. Five and it's almost hot.

What is the best way to approach this? The other load development I've done has always been with a heavier target barrel and could soak up more rounds before heating up changing velocities and POI. Would it be worth getting a barrel cooling fan? Also thought about using a temperature gun to check the barrel temperature and keep it within a certain range. Thoughts?
Thanks

PGohil
WV

 

[LCazador]

Before you do a lot load development find out if the barrel shoots better with fore end pressure or floated. You can buy temp strips to stick on the barrel from McMaster-Carr. Three shots groups but don't spend a lot of time in between shots. Conditions can change drastically if you spend too much time in between shots.

 

[PD Gohil]

Before you do a lot load development find out if the barrel shoots better with fore end pressure or floated. You can buy temp strips to stick on the barrel from McMaster-Carr. Three shots groups but don't spend a lot of time in between shots. Conditions can change drastically if you spend too much time in between shots.

I'm still new to reloading. Please explain forend pressure to me, I understand free floated, and thought it was always best to have nothing touching the action. are you saying to use factory ammo to find out if the barrel shoots better with foreign pressure or floated? I have no starting point as far as a load for this rifle. I'm gathering components in anticipation. Plan on 165g nosler partitions, with federal brass already fire formed haven't selected Powder to start with.

This rifle is strictly a hunting rifle and I dont plan for a lot of long range sessions.

 

[Bill K]

Getting ready to start load development for my Remington 700 7mm Magnum. I'm concerned because the barrel heats up rather quickly. Three shots and it's pretty warm. Five and it's almost hot.

What is the best way to approach this? The other load development I've done has always been with a heavier target barrel and could soak up more rounds before heating up changing velocities and POI. Would it be worth getting a barrel cooling fan? Also thought about using a temperature gun to check the barrel temperature and keep it within a certain range. Thoughts?
Thanks

PGohil
WV

Just shoot the 3-5 round groups and let the barrel cool. Will take you longer, but just work slow and easy, find a load that works with good groups, that you want for your hunting purpose.

 

[Treerat-sniper]

Shoot it on cooler days. I prefer fall for load development, I run several pencil barrels, take your time.

 

[Alex Wheeler]

A lot of what I do is heavy barrel BR stuff, but one of my hobbies is trying to make a sporter shoot as good. Its challenging. You have to deal with barrel heat, which means less shots over more time. I use a single shot ladder to get a rough idea of where the accuracy node will be then load 3 shot groups around that area. You really want to cover ground early on, try a lot of powders, bullets, and primers.

 

[Walt Krafft]

Back many many moons ago, I bought a 7mm mag, 10 boxes of bullets and 5 different powders. When I was done finding the magic load and the components were gone the barrel was toast. For a hunting gun, first set a realistic level of accuracy. Second, pick no more than three applicable bullets to test. Third study several reloading manuals and pick only one or two powders to test. Do your testing in three shot groups and then stop your development with the first load that meets your desired level of accuracy. Load more and confirm your load is good to go. Don't shoot out the barrel trying to get benchrest accuracy from a hunting gun. Using extra components for offhand practice will be better than more bench work.

 

[LCazador]

I'm still new to reloading. Please explain forend pressure to me, I understand free floated, and thought it was always best to have nothing touching the action. are you saying to use factory ammo to find out if the barrel shoots better with foreign pressure or floated? I have no starting point as far as a load for this rifle. I'm gathering components in anticipation. Plan on 165g nosler partitions, with federal brass already fire formed haven't selected Powder to start with.

This rifle is strictly a hunting rifle and I dont plan for a lot of long range sessions.

Free floated does not always work with lighter thinner barrels. If you're barrel is free floated you should be able to run a business card between the barrel and the stock channel. Check your reloading manual. Many manuals will list a preferred powder. Right now RE23 is a choice pick.

 

[Dusty Stevens]

I prefer 2 shot groups for hunting barrels. As long as they repeat later on the 3rd shot never made a group smaller. Ill shoot 3 shot groups to make final determinations and to get data for drop charts

 

[Homerange]

I'm still new to reloading. Please explain forend pressure to me, I understand free floated, and thought it was always best to have nothing touching the action. are you saying to use factory ammo to find out if the barrel shoots better with foreign pressure or floated?

Yes that is conventional thinking, free floated barrels are better but this don't work on a Rem Model 7 that also has a pencil thin barrel.
They have a hump near the end of the barrel groove for the barrel to pull down on when the action screws are tightened to their correct torque. 7 lbs of upward pressure is what I've read online and remove that hump at your peril and certainly a Model 7 in 6mm Rem I scored that had the barrel floated by its previous owner benefitted from some thicknesses of inner tube rubber added to replicate the factory barrel pressure.
My other Model 7 in 223 certainly shoots well enough to not consider removing the barrel groove hump.

These are both short Rem 700 actions and wood stocked so some seasonal drift could be an issue but I've not encountered it in the ranges that I shoot.
If yours sprays groups and is synthetic stocked adding a barrel bump could possibly tame it some.

 

[308 5R]

Set a timer in between shots to keep things consistent. Be cognizant of how you address/mount the rifle if you are doing this. While I certainly don’t have a wealth of experience on the subject of light rifles/barrel profiles (I have 142 documented rounds on a 5 lb rifle with a #1 contour bbl). I have quickly found out that bench technique and shooter error will kill load development data long before barrel heat with 3 shot groups and a light rifle. When you think you have found a load, repeat it over a few shooting sessions. Also, be honest with yourself with regard to calling your shots, and repeat a test if you don’t feel confident in your performance in that session or on that shot.

As with anything else, nothing is impossible.

S/F
Ryan

 

[46and2]

It is a hunting rifle. You will not be firing the most important shot with a hot barrel, so shoot for POI and groups with a cold barrel.
I bring at least 3 rifles to the range and shoot one at a time until the barrel is cool.
In warmer weather I have a Coleman rechargeable mattress pump with tubing that I pump air into the chamber after the shot, it helps a lot.

 

[mdbruce]

...I use a single shot ladder to get a rough idea of where the accuracy node will be then load 3 shot groups around that area...

Generally at what distance does the rough accuracy node in a single shot ladder show itself? The other day I saw a resurrected thread where this approach was used at 300 yards. Can you tell much from 100 yards?

 

[okie]

Generally at what distance does the rough accuracy node in a single shot ladder show itself? The other day I saw a resurrected thread where this approach was used at 300 yards. Can you tell much from 100 yards?

i can see it at 100---use same hold and rest exactly for each shot. I always remove the pressure points from the fore end, for me they shoot better. Removes one variable---it is humid here and wood changes as you go inside and outside. plastic obviously doesnt matter. I would pick a tangent ogive bullet(sierra gk or nosler ball tip etc) end get it into the lands(not enough to pull a bullet on extraction)--just get a sharpie and seat it where you can see light marks. pick a powder run a ladder. pick a node.-- be satisfied if you can get a 3-shot one inch group at 100 yds--plenty good for hunting.-- if 1.5 inch is best it will do, accept it and go on. you can spend a whole lotta money and time when it really doesnt matter.

 

[okie]

oh and to answer your question, i would shoot it cold, like hunting

 

[okie]

Yes that is conventional thinking, free floated barrels are better but this don't work on a Rem Model 7 that also has a pencil thin barrel.
They have a hump near the end of the barrel groove for the barrel to pull down on when the action screws are tightened to their correct torque. 7 lbs of upward pressure is what I've read online and remove that hump at your peril and certainly a Model 7 in 6mm Rem I scored that had the barrel floated by its previous owner benefitted from some thicknesses of inner tube rubber added to replicate the factory barrel pressure.
My other Model 7 in 223 certainly shoots well enough to not consider removing the barrel groove hump.

These are both short Rem 700 actions and wood stocked so some seasonal drift could be an issue but I've not encountered it in the ranges that I shoot.
If yours sprays groups and is synthetic stocked adding a barrel bump could possibly tame it some.

yep--i have seen this also

 

[okie]

I'm still new to reloading. Please explain forend pressure to me, I understand free floated, and thought it was always best to have nothing touching the action. are you saying to use factory ammo to find out if the barrel shoots better with foreign pressure or floated? I have no starting point as far as a load for this rifle. I'm gathering components in anticipation. Plan on 165g nosler partitions, with federal brass already fire formed haven't selected Powder to start with.

This rifle is strictly a hunting rifle and I dont plan for a lot of long range sessions.

that bullet should be easy to tune

 

[Alex Wheeler]

Generally at what distance does the rough accuracy node in a single shot ladder show itself? The other day I saw a resurrected thread where this approach was used at 300 yards. Can you tell much from 100 yards?

Generally I like to do it at the max range I would hunt with that rifle. I do a lot of it at 600. I have found multiple tunes for rifles at that distance, some hold up at 1k others dont, so you still need to verify them out farther. Same goes for 300, I have found good 300 yard tunes that held to 1k, others that went vertical. At least for me I can not tell by those groups if they will hold to 1k without trying them.

 

[okie]

Back many many moons ago, I bought a 7mm mag, 10 boxes of bullets and 5 different powders. When I was done finding the magic load and the components were gone the barrel was toast. For a hunting gun, first set a realistic level of accuracy. Second, pick no more than three applicable bullets to test. Third study several reloading manuals and pick only one or two powders to test. Do your testing in three shot groups and then stop your development with the first load that meets your desired level of accuracy. Load more and confirm your load is good to go. Don't shoot out the barrel trying to get benchrest accuracy from a hunting gun. Using extra components for offhand practice will be better than more bench work.

yep exactly

 

[dthomas]

I use 3 shot groups for my hunting rifles and let barrel cool between groups